Menopause, also known as the climacteric, is the time in most women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause typically occurs between 49 and 52 years of age. Medical professionals often define menopause as having occurred when a woman has not had any menstrual bleeding for a year. It may also be defined by a decrease in hormone production by the ovaries. In those who have had surgery to remove their uterus but still have ovaries, menopause may be considered to have occurred at the time of the surgery or when their hormone levels fell. Following the removal of the uterus, symptoms typically occur earlier, at an average of 45 years of age.
|An Ukara Ekpe textile from the Igbo culture which is secretly dyed by post-menopausal women.|
|Symptoms||No menstrual periods for a year|
|Usual onset||49 and 52 years of age|
|Causes||Usually a natural change, surgery that removes both ovaries, some types of chemotherapy|
|Treatment||None, lifestyle changes|
|Medication||Menopausal hormone therapy, clonidine, gabapentin, selective serotonin reuptake inhibitors|
In the years before menopause, a woman's periods typically become irregular, which means that periods may be longer or shorter in duration or be lighter or heavier in the amount of flow. During this time, women often experience hot flashes; these typically last from 30 seconds to ten minutes and may be associated with shivering, sweating, and reddening of the skin. Hot flashes often stop occurring after a year or two. Other symptoms may include vaginal dryness, trouble sleeping, and mood changes. The severity of symptoms varies between women. While menopause is often thought to be linked to an increase in heart disease, this primarily occurs due to increasing age and does not have a direct relationship with menopause. In some women, problems that were present like endometriosis or painful periods will improve after menopause.
Menopause is usually a natural change. It can occur earlier in those who smoke tobacco. Other causes include surgery that removes both ovaries or some types of chemotherapy. At the physiological level, menopause happens because of a decrease in the ovaries' production of the hormones estrogen and progesterone. While typically not needed, a diagnosis of menopause can be confirmed by measuring hormone levels in the blood or urine. Menopause is the opposite of menarche, the time when a girl's periods start.
Specific treatment is not usually needed. Some symptoms, however, may be improved with treatment. With respect to hot flashes, avoiding smoking, caffeine, and alcohol is often recommended. Sleeping in a cool room and using a fan may help. The following medications may help: menopausal hormone therapy (MHT), clonidine, gabapentin, or selective serotonin reuptake inhibitors. Exercise may help with sleeping problems. While MHT was once routinely prescribed, it is now only recommended in those with significant symptoms, as there are concerns about side effects. High-quality evidence for the effectiveness of alternative medicine has not been found. There is tentative evidence for phytoestrogens.
Signs and symptomsEdit
During early menopause transition, the menstrual cycles remain regular but the interval between cycles begins to lengthen. Hormone levels begin to fluctuate. Ovulation may not occur with each cycle.
The term menopause refers to a point in time that follows one year after the last menstruation. During the menopausal transition and after menopause, women can experience a wide range of symptoms.
Vagina and uterusEdit
During the transition to menopause, menstrual patterns can show shorter cycling (by 2–7 days); longer cycles remain possible. There may be irregular bleeding (lighter, heavier, spotting). Dysfunctional uterine bleeding is often experienced by women approaching menopause due to the hormonal changes that accompany the menopause transition. Spotting or bleeding may simply be related to vaginal atrophy, a benign sore (polyp or lesion), or may be a functional endometrial response. The European Menopause and Andropause Society has released guidelines for assessment of the endometrium, which is usually the main source of spotting or bleeding.
In post-menopausal women, however, any genital bleeding is an alarming symptom that requires an appropriate study to rule out the possibility of malignant diseases.
Symptoms that may appear during menopause and continue through postmenopause include:
- painful intercourse
- vaginal dryness
- atrophic vaginitis – thinning of the membranes of the vulva, the vagina, the cervix, and the outer urinary tract, along with considerable shrinking and loss in elasticity of all of the outer and inner genital areas.
Other physical symptoms of menopause include lack of energy, joint soreness, stiffness, back pain, breast enlargement, breast pain,heart palpitations, headache, dizziness, dry, itchy skin, thinning, tingling skin, weight gain, urinary incontinence,urinary urgency, interrupted sleeping patterns, heavy night sweats, and hot flashes.
Mood and memory effectsEdit
Menopause-related cognitive impairment can be confused with the mild cognitive impairment that precedes dementia. Tentative evidence has found that forgetfulness affects about half of menopausal women, and is probably caused by the effects of declining estrogen levels on the brain, or perhaps by reduced blood flow to the brain during hot flashes.
- A possible but contentious increased risk of atherosclerosis. The risk of acute myocardial infarction and other cardiovascular diseases rises sharply after menopause, but the risk can be reduced by managing risk factors, such as tobacco smoking, hypertension, increased blood lipids and body weight.
- Increased risk of osteopenia, osteoporosis, and accelerated lung function decline.
Menopause can be induced or occur naturally. Induced menopause occurs as a result of medical treatment such as chemotherapy, radiotherapy, oophorectomy, or complications of tubal ligation, hysterectomy, unilateral or bilateral salpingo-oophorectomy or leuprorelin usage.
Menopause typically occurs between 49 and 52 years of age. Half of women have their last period between the ages of 47 and 55, while 80% have their last period between 44 and 58. The average age of the last period in the United States is 51 years, in the United Kingdom is 52 years, in Ireland is 50 years and in Australia is 51 years. In India and the Philippines, the median age of natural menopause is considerably earlier, at 44 years. The menopausal transition or perimenopause leading up to menopause usually lasts 7 years (sometimes as long as 14 years).
In rare cases, a woman's ovaries stop working at a very early age, ranging anywhere from the age of puberty to age 40. This is known as premature ovarian failure and affects 1 to 2% of women by age 40.
Undiagnosed and untreated coeliac disease is a risk factor for early menopause. Coeliac disease can present with several non-gastrointestinal symptoms, in the absence of gastrointestinal symptoms, and most cases escape timely recognition and go undiagnosed, leading to a risk of long-term complications. A strict gluten-free diet reduces the risk. Women with early diagnosis and treatment of coeliac disease present a normal duration of fertile life span.
Women who have undergone hysterectomy with ovary conservation go through menopause on average 3.7 years earlier than the expected age. Other factors that can promote an earlier onset of menopause (usually 1 to 3 years early) are smoking cigarettes or being extremely thin.
Premature ovarian failureEdit
Premature ovarian failure (POF) is when the ovaries stop functioning before the age of 40 years. It is diagnosed or confirmed by high blood levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH) on at least three occasions at least four weeks apart.
Known causes of premature ovarian failure include autoimmune disorders, thyroid disease, diabetes mellitus, chemotherapy, being a carrier of the fragile X syndrome gene, and radiotherapy. However, in about 50–80% of spontaneous cases of premature ovarian failure, the cause is unknown, i.e., it is generally idiopathic.
Women who have a functional disorder affecting the reproductive system (e.g., endometriosis, polycystic ovary syndrome, cancer of the reproductive organs) can go into menopause at a younger age than the normal timeframe. The functional disorders often significantly speed up the menopausal process.
An early menopause can be related to cigarette smoking, higher body mass index, racial and ethnic factors, illnesses, and the surgical removal of the ovaries, with or without the removal of the uterus.
Rates of premature menopause have been found to be significantly higher in fraternal and identical twins; approximately 5% of twins reach menopause before the age of 40. The reasons for this are not completely understood. Transplants of ovarian tissue between identical twins have been successful in restoring fertility.
Menopause can be surgically induced by bilateral oophorectomy (removal of ovaries), which is often, but not always, done in conjunction with removal of the Fallopian tubes (salpingo-oophorectomy) and uterus (hysterectomy). Cessation of menses as a result of removal of the ovaries is called "surgical menopause". Surgical treatments, such as the removal of ovaries, might cause periods to stop altogether. The sudden and complete drop in hormone levels usually produces extreme withdrawal symptoms such as hot flashes, etc. The symptoms of early menopause may be more severe.
Removal of the uterus without removal of the ovaries does not directly cause menopause, although pelvic surgery of this type can often precipitate a somewhat earlier menopause, perhaps because of a compromised blood supply to the ovaries.. The time between surgery and possible early menopause is due to the fact that ovaries are still producing hormones.
The menopausal transition, and postmenopause itself, is a natural change, not usually a disease state or a disorder. The main cause of this transition is the natural depletion and aging of the finite amount of oocytes (ovarian reserve). This process is sometimes accelerated by other conditions and is known to occur earlier after a wide range of gynecologic procedures such as hysterectomy (with and without ovariectomy), endometrial ablation and uterine artery embolisation. The depletion of the ovarian reserve causes an increase in circulating follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels because there are fewer oocytes and follicles responding to these hormones and producing estrogen.
The transition has a variable degree of effects.
In younger women, during a normal menstrual cycle the ovaries produce estradiol, testosterone and progesterone in a cyclical pattern under the control of FSH and luteinizing hormone (LH), which are both produced by the pituitary gland. During perimenopause (approaching menopause), estradiol levels and patterns of production remain relatively unchanged or may increase compared to young women, but the cycles become frequently shorter or irregular. The often observed increase in estrogen is presumed to be in response to elevated FSH levels that, in turn, is hypothesized to be caused by decreased feedback by inhibin. Similarly, decreased inhibin feedback after hysterectomy is hypothesized to contribute to increased ovarian stimulation and earlier menopause.
The menopausal transition is characterized by marked, and often dramatic, variations in FSH and estradiol levels. Because of this, measurements of these hormones are not considered to be reliable guides to a woman's exact menopausal status.
Menopause occurs because of the sharp decrease of estradiol and progesterone production by the ovaries. After menopause, estrogen continues to be produced mostly by aromatase in fat tissues and is produced in small amounts in many other tissues such as ovaries, bone, blood vessels, and the brain where it acts locally. The substantial fall in circulating estradiol levels at menopause impacts many tissues, from brain to skin.
In contrast to the sudden fall in estradiol during menopause, the levels of total and free testosterone, as well as dehydroepiandrosterone sulfate (DHEAS) and androstenedione appear to decline more or less steadily with age. An effect of natural menopause on circulating androgen levels has not been observed. Thus specific tissue effects of natural menopause cannot be attributed to loss of androgenic hormone production.
Hot flashes and other vasomotor symptoms accompany the menopausal transition. While many sources continue to claim that hot flashes during the menopausal transition are caused by low estrogen levels, this assertion was shown incorrect in 1935, and, in most cases, hot flashes are observed despite elevated estrogen levels. The exact cause of these symptoms is not yet understood, possible factors considered are higher and erratic variation of estradiol level during the cycle, elevated FSH levels which may indicate hypothalamic dysregulation perhaps caused by missing feedback by inhibin. It has been also observed that the vasomotor symptoms differ during early perimenopause and late menopausal transition and it is possible that they are caused by a different mechanism.
Decreased inhibin feedback after hysterectomy is hypothesized to contribute to increased ovarian stimulation and earlier menopause. Hastened ovarian aging has been observed after endometrial ablation. While it is difficult to prove that these surgeries are causative, it has been hypothesized that the endometrium may be producing endocrine factors contributing to the endocrine feedback and regulation of the ovarian stimulation. Elimination of these factors contributes to faster depletion of the ovarian reserve. Reduced blood supply to the ovaries that may occur as a consequence of hysterectomy and uterine artery embolisation has been hypothesized to contribute to this effect.
Impaired DNA repair mechanisms may contribute to earlier depletion of the ovarian reserve during aging. As women age, double-strand breaks accumulate in the DNA of their primordial follicles. Primordial follicles are immature primary oocytes surrounded by a single layer of granulosa cells. An enzyme system is present in oocytes that ordinarily accurately repairs DNA double-strand breaks. This repair system is called "homologous recombinational repair", and it is especially effective during meiosis. Meiosis is the general process by which germ cells are formed in all sexual eukaryotes; it appears to be an adaptation for efficiently removing damages in germ line DNA. (See Meiosis.)
Human primary oocytes are present at an intermediate stage of meiosis, termed prophase I (see Oogenesis). Expression of four key DNA repair genes that are necessary for homologous recombinational repair during meiosis (BRCA1, MRE11, Rad51, and ATM) decline with age in oocytes. This age-related decline in ability to repair DNA double-strand damages can account for the accumulation of these damages, that then likely contributes to the depletion of the ovarian reserve.
Premenopause is a term used to mean the years leading up to the last period, when the levels of reproductive hormones are becoming more variable and lower, and the effects of hormone withdrawal are present. Premenopause starts some time before the monthly cycles become noticeably irregular in timing.
The term "perimenopause", which literally means "around the menopause", refers to the menopause transition years before the date of the final episode of flow. According to the North American Menopause Society, this transition can last for four to eight years. The Centre for Menstrual Cycle and Ovulation Research describes it as a six- to ten-year phase ending 12 months after the last menstrual period.
During perimenopause, estrogen levels average about 20–30% higher than during premenopause, often with wide fluctuations. These fluctuations cause many of the physical changes during perimenopause as well as menopause, especially during the last 1–2 years of perimenopause (before menopause). Some of these changes are hot flashes, night sweats, difficulty sleeping, mood swings, vaginal dryness or atrophy, incontinence, osteoporosis, and heart disease. During this period, fertility diminishes but is not considered to reach zero until the official date of menopause. The official date is determined retroactively, once 12 months have passed after the last appearance of menstrual blood.
The menopause transition typically begins between 40 and 50 years of age (average 47.5). The duration of perimenopause may be for up to eight years. Women will often, but not always, start these transitions (perimenopause and menopause) about the same time as their mother did.
In some women, menopause may bring about a sense of loss related to the end of fertility. In addition, this change often occurs when other stressors may be present in a woman's life:
- Caring for, and/or the death of, elderly parents
- Empty nest syndrome when children leave home
- The birth of grandchildren, which places people of "middle age" into a new category of "older people" (especially in cultures where being older is a state that is looked down on)
Some research appears to show that melatonin supplementation in perimenopausal women can improve thyroid function and gonadotropin levels, as well as restoring fertility and menstruation and preventing depression associated with menopause.
The term "postmenopausal" describes women who have not experienced any menstrual flow for a minimum of 12 months, assuming that they have a uterus and are not pregnant or lactating. In women without a uterus, menopause or postmenopause can be identified by a blood test showing a very high FSH level. Thus postmenopause is the time in a woman's life that takes place after her last period or, more accurately, after the point when her ovaries become inactive.
The reason for this delay in declaring postmenopause is because periods are usually erratic at this time of life. Therefore, a reasonably long stretch of time is necessary to be sure that the cycling has ceased. At this point a woman is considered infertile; however, the possibility of becoming pregnant has usually been very low (but not quite zero) for a number of years before this point is reached.
A woman's reproductive hormone levels continue to drop and fluctuate for some time into post-menopause, so hormone withdrawal effects such as hot flashes may take several years to disappear.
A period-like flow during postmenopause, even spotting, may be a sign of endometrial cancer.
Perimenopause is a natural stage of life. It is not a disease or a disorder. Therefore, it does not automatically require any kind of medical treatment. However, in those cases where the physical, mental, and emotional effects of perimenopause are strong enough that they significantly disrupt the life of the woman experiencing them, palliative medical therapy may sometimes be appropriate.
Hormone replacement therapyEdit
HRT may be reasonable for the treatment of menopausal symptoms, such as hot flashes. It is the most effective treatment option, especially when delivered as a skin patch. Its use, however, appears to increase the risk of strokes and blood clots. When used for menopausal symptoms some recommend it be used for the shortest time possible and at the lowest dose possible. Evidence to support long-term use, however, is poor.
HRT may be unsuitable for some women, including those at increased risk of cardiovascular disease, increased risk of thromboembolic disease (such as those with obesity or a history of venous thrombosis) or increased risk of some types of cancer. There is some concern that this treatment increases the risk of breast cancer.
Adding testosterone to hormone therapy has a positive effect on sexual function in postmenopausal women, although it may be accompanied by hair growth, acne and a reduction in high-density lipoprotein (HDL) cholesterol. These side effects diverge depending on the doses and methods of using testosterone.
Selective estrogen receptor modulatorsEdit
SERMs are a category of drugs, either synthetically produced or derived from a botanical source, that act selectively as agonists or antagonists on the estrogen receptors throughout the body. The most commonly prescribed SERMs are raloxifene and tamoxifen. Raloxifene exhibits oestrogen agonist activity on bone and lipids, and antagonist activity on breast and the endometrium. Tamoxifen is in widespread use for treatment of hormone sensitive breast cancer. Raloxifene prevents vertebral fractures in postmenopausal, osteoporotic women and reduces the risk of invasive breast cancer.
Some of the SSRIs and SNRIs appear to provide some relief from vasomotor symptoms. Low dose paroxetine is the only non-hormonal medication that was FDA-approved to treat moderate-to-severe vasomotor symptoms associated with menopause as of 2016. They may, however, be associated with appetite and sleeping problems, constipation and nausea.
Gabapentin or clonidine may help but do not work as well as hormone therapy. Gabapentin can decrease the amount of hot flashes. Side effects associated with its use include drowsiness and headaches. Clonidine is used to improve vasomotor symptoms and may be associated with constipation, dizziness, nausea and sleeping problems.
Exercise has been thought to reduce postmenopausal symptoms through the increase of endorphin levels, which decrease as estrogen production decreases. Additionally, high BMI is a risk factor for vasomotor symptoms in particular. However, there is insufficient evidence to support the benefits of weight loss for symptom management. There are mixed perspectives on the benefits of physical exercise. While one review found that there was a lack of quality evidence supporting a benefit of exercise, another review recommended regular healthy exercise to reduce comorbidities, improve mood and anxiety symptoms, enhance cognition, and decrease the risk of fractures. Yoga may help with postmenopausal symptoms similar to other exercise.
There is no evidence of consistent benefit of alternative therapies for menopausal symptoms despite their popularity.
The effect of soy isoflavones on menopausal symptoms is promising for reduction of hot flashes and vaginal dryness. Evidence does not support a benefit from phytoestrogens such as coumestrol, femarelle, or the non-phytoestrogen black cohosh. As of 2011 there is no support for herbal or dietary supplements in the prevention or treatment of the mental changes that occur around menopause.
Hypnosis may reduce the severity of hot flashes. In addition, relaxation training with at-home relaxation audiotapes such as deep breathing, paced respiration, and guided imagery may have positive effects on relaxing muscles and reducing stress.
There is no evidence to support the efficacy of acupuncture as a management for menopausal symptoms. A 2016 Cochrane review found not enough evidence to show a difference between Chinese herbal medicine and placebo for the vasomotor symptoms.
- Lack of lubrication is a common problem during and after perimenopause. Vaginal moisturizers can help women with overall dryness, and lubricants can help with lubrication difficulties that may be present during intercourse. It is worth pointing out that moisturizers and lubricants are different products for different issues: some women complain that their genitalia are uncomfortably dry all the time, and they may do better with moisturizers. Those who need only lubricants do well using them only during intercourse.
- Low-dose prescription vaginal estrogen products such as estrogen creams are generally a safe way to use estrogen topically, to help vaginal thinning and dryness problems (see vaginal atrophy) while only minimally increasing the levels of estrogen in the bloodstream.
- In terms of managing hot flashes, lifestyle measures such as drinking cold liquids, staying in cool rooms, using fans, removing excess clothing, and avoiding hot flash triggers such as hot drinks, spicy foods, etc., may partially supplement (or even obviate) the use of medications for some women.
- Individual counseling or support groups can sometimes be helpful to handle sad, depressed, anxious or confused feelings women may be having as they pass through what can be for some a very challenging transition time.
- Osteoporosis can be minimized by smoking cessation, adequate vitamin D intake and regular weight-bearing exercise. The bisphosphate drug alendronate may decrease the risk of a fracture, in women that have both bone loss and a previous fracture and less so for those with just osteoporosis.
- A surgical procedure where a part of one of the ovaries is removed earlier in life and frozen and then over time thawed and returned to the body has been tried. While at least 11 women have undergone the procedure and paid over £6,000, there is no evidence it is safe or effective.
Society and cultureEdit
The cultural context within which a woman lives can have a significant impact on the way she experiences the menopausal transition. Menopause has been described as a subjective experience, with social and cultural factors playing a prominent role in the way menopause is experienced and perceived.
The word menopause was invented by French doctors at the beginning of the nineteenth century. Some of them noted that peasant women had no complaints about the end of menses, while urban middle-class women had many troubling symptoms. Doctors at this time considered the symptoms to be the result of urban lifestyles of sedentary behaviour, alcohol consumption, too much time indoors, and over-eating, with a lack of fresh fruit and vegetables. Within the United States, social location affects the way women perceive menopause and its related biological effects. Research indicates that whether a woman views menopause as a medical issue or an expected life change is correlated with her socio-economic status. The paradigm within which a woman considers menopause influences the way she views it: Women who understand menopause as a medical condition rate it significantly more negatively than those who view it as a life transition or a symbol of aging.
Ethnicity and geography play roles in the experience of menopause. American women of different ethnicities report significantly different types of menopausal effects. One major study found Caucasian women most likely to report what are sometimes described as psychosomatic symptoms, while African-American women were more likely to report vasomotor symptoms.
It seems that Japanese women experience menopause effects, or konenki, in a different way from American women. Japanese women report lower rates of hot flashes and night sweats; this can be attributed to a variety of factors, both biological and social. Historically, konenki was associated with wealthy middle-class housewives in Japan, i.e., it was a "luxury disease" that women from traditional, inter-generational rural households did not report. Menopause in Japan was viewed as a symptom of the inevitable process of aging, rather than a "revolutionary transition", or a "deficiency disease" in need of management.
In Japanese culture, reporting of vasomotor symptoms has been on the increase, with research conducted by Melissa Melby in 2005 finding that of 140 Japanese participants, hot flashes were prevalent in 22.1%. This was almost double that of 20 years prior. Whilst the exact cause for this is unknown, possible contributing factors include significant dietary changes, increased medicalisation of middle-aged women and increased media attention on the subject. However, reporting of vasomotor symptoms is still significantly lower than North America.
Additionally, while most women in the United States apparently have a negative view of menopause as a time of deterioration or decline, some studies seem to indicate that women from some Asian cultures have an understanding of menopause that focuses on a sense of liberation and celebrates the freedom from the risk of pregnancy. Diverging from these conclusions, one study appeared to show that many American women "experience this time as one of liberation and self-actualization".
Menopause literally means the "end of monthly cycles" (the end of monthly periods or menstruation), from the Greek word pausis ("pause") and mēn ("month"). This is a medical calque; the Greek word for menses is actually different. In Ancient Greek, the menses were described in the plural, ta emmēnia, ("the monthlies"), and its modern descendant has been clipped to ta emmēna. The Modern Greek medical term is emmenopausis in Katharevousa or emmenopausi in Demotic Greek.
The word "menopause" was coined specifically for human females, where the end of fertility is traditionally indicated by the permanent stopping of monthly menstruations. However, menopause exists in some other animals, many of which do not have monthly menstruation; in this case, the term means a natural end to fertility that occurs before the end of the natural lifespan.
Few animals have a menopause: humans are joined by just four other species in which females live substantially longer than their ability to reproduce. The others are all cetaceans: beluga whales, narwhals, killer whales and short-finned pilot whales. Various theories have been suggested that attempt to suggest evolutionary benefits to the human species stemming from the cessation of women's reproductive capability before the end of their natural lifespan. Explanations can be categorized as adaptive and non-adaptive:
The high cost of female investment in offspring may lead to physiological deteriorations that amplify susceptibility to becoming infertile. This hypothesis suggests the reproductive lifespan in humans has been optimized, but it has proven more difficult in females and thus their reproductive span is shorter. If this hypothesis were true, however, age at menopause should be negatively correlated with reproductive effort, and the available data do not support this.
A recent increase in female longevity due to improvements in the standard of living and social care has also been suggested. It is difficult for selection, however, to favor aid to offspring from parents and grandparents. Irrespective of living standards, adaptive responses are limited by physiological mechanisms. In other words, senescence is programmed and regulated by specific genes.
Early human selection shadowEdit
While it is fairly common for extant hunter-gatherers to live past age 50 provided that they survive childhood, fossil evidence shows that mortality in adults has decreased over the last 30,000 to 50,000 years and that it was extremely unusual for early Homo sapiens to live to age 50. This discovery has led some biologists to argue that there was no selection for or against menopause at the time at which the ancestor of all modern humans lived in Africa, suggesting that menopause is instead a random evolutionary effect of a selection shadow regarding aging in early Homo sapiens. It is also argued that since the population fraction of post-menopausal women in early Homo sapiens was so low, menopause had no evolutionary effect on mate selection or social behaviors related to mate selection.
"Survival of the fittest" hypothesisEdit
This hypothesis suggests that younger mothers and offspring under their care will fare better in a difficult and predatory environment because a younger mother will be stronger and more agile in providing protection and sustenance for herself and a nursing baby. The various biological factors associated with menopause had the effect of male members of the species investing their effort with the most viable of potential female mates.[page needed] One problem with this hypothesis is that we would expect to see menopause exhibited in the animal kingdom, and another problem is that in the case of extended child development, even a female who was relatively young, still agile, and attractive when producing a child would lose future support from her male partner due to him seeking out fertile mates when she reaches menopause while the child is still not independent. That would be counterproductive to the supposed adaptation of getting male support as a fertile female and ruin survival for children produced over much of the female's fertile and agile life, unless children were raised in ways that did not rely on support from a male partner which would eliminate that type of resource diverting selection anyway.
Young female preference hypothesisEdit
The young female preference hypothesis proposes that changes in male preferences for younger mates allowed late-age acting fertility mutations to accumulate in females without any evolutionary penalty, giving rise to menopause. A computer model was constructed to test this hypothesis, and showed that it was feasible. However, in order for deleterious mutations that affect fertility past roughly age fifty to accumulate, human maximum lifespan had to first be extended to about its present value. As of 2016 it was unclear if there has been sufficient time since that happened for such an evolutionary process to occur.
Male-biased philopatry hypothesisEdit
The male-biased philopatry theory proposes that male-biased philopatry in social species leads to increased relatedness to the group in relation to female age, making inclusive fitness benefits older females receive from helping the group greater than what they would receive from continued reproduction, which eventually led to the evolution of menopause. In a pattern of male-biased dispersal and local mating, the relatedness of the individuals in the group decreases with female age, leading to a decrease in kin selection with female age. This occurs because a female will stay with her father in her natal group throughout life, initially being closely related to the males and females. Females are born and stay in the group, so relatedness to the females stays about the same. However, throughout time, the older male relatives will die and any sons she gives birth to will disperse, so that local relatedness to males, and therefore the whole group, declines. The situation is reversed in species where males are philopatric and either females disperse, or mating is non-local. Under these conditions, a female's reproductive life begins away from her father and paternal relatives because she was either born into a new group from non-local mating or because she dispersed. In the case of female-biased dispersal, the female is initially equally unrelated with every individual in the group, and with non-local mating, the female is closely related to the females of the group, but not the males since her paternal relatives are in another group. As she gives birth, her sons will stay with her, increasing her relatedness to males in the group overtime and thus her relatedness with the overall group. The common feature that connects these two otherwise different behaviors is male-biased philopatry, which leads to an increase in kin selection with female age.
While not conclusive, evidence does exist to support the idea that female-biased dispersal existed in pre-modern humans. The closest living relatives to humans, chimpanzees, bonobos, and both mountain gorillas and western lowland gorillas, are female-biased dispersers. Analysis of sex specific genetic material, the non-recombining portions of the Y chromosome and mitochondrial DNA, show evidence of a prevalence of female-biased dispersal as well; however, these results could also be affected by the effective breeding numbers of males and females in local populations. Evidence of female-biased dispersion in hunter-gatherers is not definitive, with some studies supporting the idea, and others suggesting there is no strong bias towards either sex. In killer whales, both sexes mate non-locally with members of a different pod but return to the pod after copulation. Demographic data shows that a female's mean relatedness to the group does increase over time due to increasing relatedness to males. While less well-studied, there is evidence that short-finned pilot whales, another menopausal species, also display this behavior. However, mating behavior that increases local relatedness with female age is prevalent in non-menopausal species, making it unlikely that it is the only factor that determines if menopause will evolve in a species.
The mother hypothesis suggests that menopause was selected for humans because of the extended development period of human offspring and high costs of reproduction so that mothers gain an advantage in reproductive fitness by redirecting their effort from new offspring with a low survival chance to existing children with a higher survival chance.
The grandmother hypothesis suggests that menopause was selected for humans because it promotes the survival of grandchildren. According to this hypothesis, post-reproductive women feed and care for children, adult nursing daughters, and grandchildren whose mothers have weaned them. Human babies require large and steady supplies of glucose to feed the growing brain. In infants in the first year of life, the brain consumes 60% of all calories, so both babies and their mothers require a dependable food supply. Some evidence suggests that hunters contribute less than half the total food budget of most hunter-gatherer societies, and often much less than half, so that foraging grandmothers can contribute substantially to the survival of grandchildren at times when mothers and fathers are unable to gather enough food for all of their children. In general, selection operates most powerfully during times of famine or other privation. So although grandmothers might not be necessary during good times, many grandchildren cannot survive without them during times of famine. Arguably, however, there is no firm consensus on the supposed evolutionary advantages (or simply neutrality) of menopause to the survival of the species in the evolutionary past.
Indeed, analysis of historical data found that the length of a female's post-reproductive lifespan was reflected in the reproductive success of her offspring and the survival of her grandchildren. Another study found comparative effects but only in the maternal grandmother—paternal grandmothers had a detrimental effect on infant mortality (probably due to paternity uncertainty). Differing assistance strategies for maternal and paternal grandmothers have also been demonstrated. Maternal grandmothers concentrate on offspring survival, whereas paternal grandmothers increase birth rates.
Some believe a problem concerning the grandmother hypothesis is that it requires a history of female philopatry, while in the present day the majority of hunter-gatherer societies are patrilocal. However, there is disagreement split along ideological lines about whether patrilineality would have existed before modern times. Some believe variations on the mother, or grandmother effect fail to explain longevity with continued spermatogenesis in males (oldest verified paternity is 94 years, 35 years beyond the oldest documented birth attributed to females). Notably, the survival time past menopause is roughly the same as the maturation time for a human child. That a mother's presence could aid in the survival of a developing child, while an unidentified father's absence might not have affected survival, could explain the paternal fertility near the end of the father's lifespan. A man with no certainty of which children are his may merely attempt to father additional children, with support of existing children present but small. Note the existence of partible paternity supporting this. Some argue that the mother and grandmother hypotheses fail to explain the detrimental effects of losing ovarian follicular activity, such as osteoporosis, osteoarthritis, Alzheimer's disease and coronary artery disease.
The theories discussed above assume that evolution directly selected for menopause. Another theory states that menopause is the byproduct of the evolutionary selection for follicular atresia, a factor that causes menopause. Menopause results from having too few ovarian follicles to produce enough estrogen to maintain the ovarian-pituitary-hypothalamic loop, which results in the cessation of menses and the beginning of menopause. Human females are born with approximately a million oocytes, and approximately 400 oocytes are lost to ovulation throughout life.
Reproductive conflict hypothesisEdit
In social vertebrates, the sharing of resources among the group places limits on how many offspring can be produced and supported by members of the group. This creates a situation in which each female must compete with others of the group to ensure they are the one that reproduces. The reproductive conflict hypothesis proposes that this female reproductive conflict favors the cessation of female reproductive potential in older age to avoid reproductive conflict, increasing the older female's fitness through inclusive benefits. Female-biased dispersal or non-local mating leads to an increase in relatedness to the social group with female age. In the human case of female-biased dispersal, when a young female enters a new group, she is not related to any individual and she reproduces to produce an offspring with a relatedness of 0.5. An older female could also choose to reproduce, producing an offspring with a relatedness of 0.5, or she could refrain from reproducing and allow another pair to reproduce. Because her relatedness to males in the group is high, there is a fair probability that the offspring will be her grandchild with a relatedness of 0.25. The younger female experiences no cost to her inclusive fitness from using the resources necessary to successfully rear offspring since she is not related to members of the group, but there is a cost for the older female. As a result, the younger female has the advantage in reproductive competition. Although a female killer whale born into a social group is related to some members of the group, the whale case of non-local mating leads to similar outcomes because the younger female relatedness to the group as a whole is less than the relatedness of the older female. This behavior makes more likely the cessation of reproduction late in life to avoid reproductive conflict with younger females.
Research using both human and killer whale demographic data has been published that supports the role of reproductive conflict in the evolution of menopause. Analysis of demographic data from pre-industrial Finnish populations found significant reductions in offspring survivorship when mothers-in-laws and daughters-in-laws had overlapping births, supporting the idea that avoiding reproductive conflict is beneficial to offspring survivorship. Humans, more so than other primates, rely on food sharing for survival, so the large survivorship reduction values could be caused by a straining of community resources. Avoiding such straining is a possible explanation for why the reproductive overlap seen in humans is much lower than other primates. Food sharing is also prevalent among another menopausal species, killer whales. Reproductive conflict has also been observed in killer whales, with increased calf mortality seen when reproductive overlap between a younger and older generational female occurred.
Menopause in the animal kingdom appears to be uncommon, but the presence of this phenomenon in different species has not been thoroughly researched. Life histories show a varying degree of senescence; rapid senescing organisms (e.g., Pacific salmon and annual plants) do not have a post-reproductive life-stage. Gradual senescence is exhibited by all placental mammalian life histories.
Menopause has been observed in several species of nonhuman primates, including rhesus monkeys and chimpanzees. Menopause also has been reported in a variety of other vertebrate species including elephants, short-finned pilot whales, killer whales, narwhals, beluga whales, the guppy, the platyfish, the budgerigar, the laboratory rat and mouse, and the opossum. However, with the exception of the short-finned pilot whale, killer whale, narwhals, and beluga whales, such examples tend to be from captive individuals, and thus they are not necessarily representative of what happens in natural populations in the wild.
Dogs do not experience menopause; the canine estrus cycle simply becomes irregular and infrequent. Although older female dogs are not considered good candidates for breeding, offspring have been produced by older animals. Similar observations have been made in cats.
- Chuku G (2005). Igbo women and economic transformation in southeastern Nigeria, 1900–1960. Paragraph 3: Routledge. p. 73. ISBN 978-0415972109. Archived from the original on 19 May 2016.CS1 maint: location (link)
- "Menopause: Overview". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 28 June 2013. Archived from the original on 2 April 2015. Retrieved 8 March 2015.
- Takahashi TA, Johnson KM (May 2015). "Menopause". The Medical Clinics of North America. 99 (3): 521–34. doi:10.1016/j.mcna.2015.01.006. PMID 25841598.
- "What is menopause?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 28 June 2013. Archived from the original on 19 March 2015. Retrieved 8 March 2015.
- "What causes menopause?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 6 May 2013. Archived from the original on 2 April 2015. Retrieved 8 March 2015.
- "What are the treatments for other symptoms of menopause?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 28 June 2013. Archived from the original on 20 March 2015. Retrieved 8 March 2015.
- Krause MS, Nakajima ST (March 2015). "Hormonal and nonhormonal treatment of vasomotor symptoms". Obstetrics and Gynecology Clinics of North America. 42 (1): 163–79. doi:10.1016/j.ogc.2014.09.008. PMID 25681847.
- "Menopause: Overview". PubMedHealth. 29 August 2013. Archived from the original on 10 September 2017. Retrieved 8 March 2015.
- Sievert, Lynnette Leidy (2006). Menopause : a biocultural perspective ([Online-Ausg.] ed.). New Brunswick, N.J.: Rutgers University Press. p. 81. ISBN 9780813538563. Archived from the original on 10 September 2017.
- International position paper on women's health and menopause : a comprehensive approach. DIANE Publishing. 2002. p. 36. ISBN 9781428905214. Archived from the original on 10 September 2017.
- "What are the symptoms of menopause?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 6 May 2013. Archived from the original on 20 March 2015. Retrieved 8 March 2015.
- "What Is Menopause?". National Institute on Aging. Retrieved 6 October 2018.
- Warren, volume editors, Claudio N. Soares, Michelle (2009). The menopausal transition : interface between gynecology and psychiatry ([Online-Ausg.] ed.). Basel: Karger. p. 73. ISBN 978-3805591010.
- "How do health care providers diagnose menopause?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 6 May 2013. Archived from the original on 2 April 2015. Retrieved 8 March 2015.
- Wood, James. "9". Dynamics of Human Reproduction: Biology, Biometry, Demography. Transaction Publishers. p. 401. ISBN 9780202365701. Archived from the original on 10 September 2017.
- Franco OH, Chowdhury R, Troup J, Voortman T, Kunutsor S, Kavousi M, Oliver-Williams C, Muka T (June 2016). "Use of Plant-Based Therapies and Menopausal Symptoms: A Systematic Review and Meta-analysis". JAMA. 315 (23): 2554–63. doi:10.1001/jama.2016.8012. PMID 27327802.
- Hoffman, Barbara (2012). Williams Gynecology. New York: McGraw-Hill Medical. pp. 555–56. ISBN 9780071716727.
- Dreisler E, Poulsen LG, Antonsen SL, Ceausu I, Depypere H, Erel CT, Lambrinoudaki I, Pérez-López FR, Simoncini T, Tremollieres F, Rees M, Ulrich LG (June 2013). "EMAS clinical guide: assessment of the endometrium in peri and postmenopausal women". Maturitas. 75 (2): 181–90. doi:10.1016/j.maturitas.2013.03.011. PMID 23619009.
- Pérez-López FR, Cuadros JL, Fernández-Alonso AM, Chedraui P, Sánchez-Borrego R, Monterrosa-Castro A (December 2012). "Urinary incontinence, related factors and menopause-related quality of life in mid-aged women assessed with the Cervantes Scale". Maturitas. 73 (4): 369–72. doi:10.1016/j.maturitas.2012.09.004. PMID 23041251.
- Chedraui P, Pérez-López FR, Mendoza M, Leimberg ML, Martínez MA, Vallarino V, Hidalgo L (January 2010). "Factors related to increased daytime sleepiness during the menopausal transition as evaluated by the Epworth sleepiness scale". Maturitas. 65 (1): 75–80. doi:10.1016/j.maturitas.2009.11.003. PMID 19945237.
- Arakane M, Castillo C, Rosero MF, Peñafiel R, Pérez-López FR, Chedraui P (June 2011). "Factors relating to insomnia during the menopausal transition as evaluated by the Insomnia Severity Index". Maturitas. 69 (2): 157–61. doi:10.1016/j.maturitas.2011.02.015. PMID 21444163.
- Monterrosa-Castro A, Marrugo-Flórez M, Romero-Pérez I, Chedraui P, Fernández-Alonso AM, Pérez-López FR (April 2013). "Prevalence of insomnia and related factors in a large mid-aged female Colombian sample". Maturitas. 74 (4): 346–51. doi:10.1016/j.maturitas.2013.01.009. PMID 23391501.
- Llaneza P, García-Portilla MP, Llaneza-Suárez D, Armott B, Pérez-López FR (February 2012). "Depressive disorders and the menopause transition". Maturitas. 71 (2): 120–30. doi:10.1016/j.maturitas.2011.11.017. PMID 22196311.
- Panay, Nick; Briggs, Paula; Kovacs, Gab (20 August 2015). "Memory and Mood in the Menopause". Managing the Menopause: 21st Century Solutions. Cambridge University Press. ISBN 9781316352717.
- Birkhaeuser, Martin; Genazzani, Andrea R. (30 January 2018). Pre-Menopause, Menopause and Beyond: Volume 5: Frontiers in Gynecological Endocrinology. Springer. pp. 38–39. ISBN 9783319635408.
- Papadakis, Maxine A.; McPhee, Stephen J.; Rabow, Michael W. (11 September 2017). Current Medical Diagnosis and Treatment 2018, 57th Edition. McGraw Hill Professional. p. 1212. ISBN 9781259861499.
- Mitchell RS, Kumar V, Abbas AK, Fausto N (2007). Robbins Basic Pathology: With Student Consult Online Access (8th ed.). Philadelphia: Saunders. p. 344. ISBN 978-1-4160-2973-1.
- Souza HC, Tezini GC (September 2013). "Autonomic Cardiovascular Damage during Post-menopause: the Role of Physical Training". Aging and Disease. 4 (6): 320–8. doi:10.14336/AD.2013.0400320. PMC 3843649. PMID 24307965.
- ESHRE Capri Workshop Group (2011). "Perimenopausal risk factors and future health". Human Reproduction Update. 17 (5): 706–17. doi:10.1093/humupd/dmr020. PMID 21565809.
- Finkelstein JS, Brockwell SE, Mehta V, Greendale GA, Sowers MR, Ettinger B, Lo JC, Johnston JM, Cauley JA, Danielson ME, Neer RM (March 2008). "Bone mineral density changes during the menopause transition in a multiethnic cohort of women". The Journal of Clinical Endocrinology and Metabolism. 93 (3): 861–8. doi:10.1210/jc.2007-1876. PMC 2266953. PMID 18160467.
- Amaral AF, Strachan DP, Gómez Real F, Burney PG, Jarvis DL (November 2016). "Lower lung function associates with cessation of menstruation: UK Biobank data" (PDF). The European Respiratory Journal. 48 (5): 1288–1297. doi:10.1183/13993003.00412-2016. PMID 27660514.
- Triebner K, Matulonga B, Johannessen A, Suske S, Benediktsdóttir B, Demoly P, Dharmage SC, Franklin KA, Garcia-Aymerich J, Gullón Blanco JA, Heinrich J, Holm M, Jarvis D, Jõgi R, Lindberg E, Moratalla Rovira JM, Muniozguren Agirre N, Pin I, Probst-Hensch N, Puggini L, Raherison C, Sánchez-Ramos JL, Schlünssen V, Sunyer J, Svanes C, Hustad S, Leynaert B, Gómez Real F (April 2017). "Menopause Is Associated with Accelerated Lung Function Decline". American Journal of Respiratory and Critical Care Medicine. 195 (8): 1058–1065. doi:10.1164/rccm.201605-0968OC. hdl:10044/1/43123. PMID 27907454.
- "Early or premature menopause". Womenshealth.gov. 12 July 2017. Retrieved 7 November 2018.
- Muka T, Oliver-Williams C, Kunutsor S, Laven JS, Fauser BC, Chowdhury R, Kavousi M, Franco OH (October 2016). "Association of Age at Onset of Menopause and Time Since Onset of Menopause With Cardiovascular Outcomes, Intermediate Vascular Traits, and All-Cause Mortality: A Systematic Review and Meta-analysis". JAMA Cardiology. 1 (7): 767–776. doi:10.1001/jamacardio.2016.2415. hdl:1983/2604a547-3aec-42d7-b297-85c2954eab89. PMID 27627190.
- "Gynaecologic Problems: Menopausal Problems". Health on the Net Foundation. Retrieved 22 February 2012.
- Morabia, A; Costanza, MC (15 December 1998). "International variability in ages at menarche, first livebirth, and menopause. World Health Organization Collaborative Study of Neoplasia and Steroid Contraceptives". American Journal of Epidemiology. 148 (12): 1195–205. doi:10.1093/oxfordjournals.aje.a009609. PMID 9867266.
- Ringa V (2000). "Menopause and treatments". Quality of Life Research. 9 (6): 695–707. doi:10.1023/A:1008913605129. JSTOR 4036942.
- Podfigurna-Stopa A, Czyzyk A, Grymowicz M, Smolarczyk R, Katulski K, Czajkowski K, Meczekalski B (September 2016). "Premature ovarian insufficiency: the context of long-term effects". Journal of Endocrinological Investigation. 39 (9): 983–90. doi:10.1007/s40618-016-0467-z. PMC 4987394. PMID 27091671.
- Tersigni C, Castellani R, de Waure C, Fattorossi A, De Spirito M, Gasbarrini A, Scambia G, Di Simone N (2014). "Celiac disease and reproductive disorders: meta-analysis of epidemiologic associations and potential pathogenic mechanisms". Human Reproduction Update. 20 (4): 582–93. doi:10.1093/humupd/dmu007. PMID 24619876.
- Lasa JS, Zubiaurre I, Soifer LO (2014). "Risk of infertility in patients with celiac disease: a meta-analysis of observational studies". Arquivos de Gastroenterologia. 51 (2): 144–50. doi:10.1590/S0004-28032014000200014. PMID 25003268.
- Healthline (2 July 2014). "What causes early menopause". Healthline. Archived from the original on 28 September 2013.
- Laissue P (August 2015). "Aetiological coding sequence variants in non-syndromic premature ovarian failure: From genetic linkage analysis to next generation sequencing". Molecular and Cellular Endocrinology (Review). 411: 243–57. doi:10.1016/j.mce.2015.05.005. PMID 25960166.
- Fenton AJ (2015). "Premature ovarian insufficiency: Pathogenesis and management". Journal of Mid-Life Health (Review). 6 (4): 147–53. doi:10.4103/0976-7800.172292. PMC 4743275. PMID 26903753.
- Kalantaridou SN, Davis SR, Nelson LM. Endocrinology Metabolism Clinics of North America, December 1998; 27(4) 989–1006.
- Bucher, et al. 1930
- Harlow SD, Gass M, Hall JE, Lobo R, Maki P, Rebar RW, Sherman S, Sluss PM, de Villiers TJ (April 2012). "Executive summary of the Stages of Reproductive Aging Workshop + 10: addressing the unfinished agenda of staging reproductive aging". Fertility and Sterility. 97 (4): 843–51. doi:10.1016/j.fertnstert.2012.01.128. PMC 3340904. PMID 22341880.
- Cohen LS, Soares CN, Vitonis AF, Otto MW, Harlow BL (April 2006). "Risk for new onset of depression during the menopausal transition: the Harvard study of moods and cycles". Archives of General Psychiatry. The Harvard Study of Moods and Cycles. 63 (4): 385–90. doi:10.1001/archpsyc.63.4.385. PMID 16585467.
- Soules MR, Sherman S, Parrott E, Rebar R, Santoro N, Utian W, Woods N (December 2001). "Executive summary: Stages of Reproductive Aging Workshop (STRAW)". Climacteric. 4 (4): 267–72. doi:10.1080/cmt.4.4.267.272. PMID 11770182.
- Prior JC (August 1998). "Perimenopause: the complex endocrinology of the menopausal transition". Endocrine Reviews. 19 (4): 397–428. doi:10.1210/edrv.19.4.0341. PMID 9715373.
- Burger HG (January 1994). "Diagnostic role of follicle-stimulating hormone (FSH) measurements during the menopausal transition--an analysis of FSH, oestradiol and inhibin". European Journal of Endocrinology. 130 (1): 38–42. doi:10.1530/eje.0.1300038. PMID 8124478.
- Nahás E, Pontes A, Traiman P, NahásNeto J, Dalben I, De Luca L (April 2003). "Inhibin B and ovarian function after total abdominal hysterectomy in women of reproductive age". Gynecological Endocrinology. 17 (2): 125–31. doi:10.1080/713603218. PMID 12737673.
- Petri Nahás EA, Pontes A, Nahas-Neto J, Borges VT, Dias R, Traiman P (February 2005). "Effect of total abdominal hysterectomy on ovarian blood supply in women of reproductive age". Journal of Ultrasound in Medicine. 24 (2): 169–74. doi:10.7863/jum.2005.24.2.169. PMID 15661947.
- Simpson ER, Davis SR (November 2001). "Minireview: aromatase and the regulation of estrogen biosynthesis--some new perspectives". Endocrinology. 142 (11): 4589–94. doi:10.1210/en.142.11.4589. PMID 11606422.
- Davison SL, Bell R, Donath S, Montalto JG, Davis SR (July 2005). "Androgen levels in adult females: changes with age, menopause, and oophorectomy". The Journal of Clinical Endocrinology and Metabolism. 90 (7): 3847–53. doi:10.1210/jc.2005-0212. PMID 15827095.
- Fogle RH, Stanczyk FZ, Zhang X, Paulson RJ (August 2007). "Ovarian androgen production in postmenopausal women". The Journal of Clinical Endocrinology and Metabolism. 92 (8): 3040–3. doi:10.1210/jc.2007-0581. PMID 17519304.
- Titus S, Li F, Stobezki R, Akula K, Unsal E, Jeong K, Dickler M, Robson M, Moy F, Goswami S, Oktay K (February 2013). "Impairment of BRCA1-related DNA double-strand break repair leads to ovarian aging in mice and humans". Science Translational Medicine. 5 (172): 172ra21. doi:10.1126/scitranslmed.3004925. PMC 5130338. PMID 23408054.
- Greene JG (May 1998). "Constructing a standard climacteric scale". Maturitas. 29 (1): 25–31. doi:10.1016/s0378-5122(98)00025-5. PMID 9643514.
- Monterrosa-Castro A, Romero-Pérez I, Marrugo-Flórez M, Fernández-Alonso AM, Chedraui P, Pérez-López FR (August 2012). "Quality of life in a large cohort of mid-aged Colombian women assessed using the Cervantes Scale". Menopause. 19 (8): 924–30. doi:10.1097/gme.0b013e318247908d. PMID 22549166.
- Schneider HP, Naftolin F (2005). Climacteric medicine where do we go?. London: Taylor & Francis. p. 28. ISBN 9780203024966.
- "What Is Perimenopause?". WebMD. Retrieved 6 October 2018.
- "Perimenopause - Symptoms and causes". Mayo Clinic. Retrieved 6 October 2018.
- "Menopause 101". A primer for the perimenopausal. The North American Menopause Society. Archived from the original on 10 April 2013. Retrieved 11 April 2013.
- Prior J. "Perimenopause". Centre for Menstrual Cycle and Ovulation Research (CeMCOR). Archived from the original on 25 February 2013. Retrieved 10 May 2013.
- Chichester M, Ciranni P (August–September 2011). "Approaching menopause (but not there yet!): caring for women in midlife". Nursing for Women's Health. 15 (4): 320–4. doi:10.1111/j.1751-486X.2011.01652.x. PMID 21884497.
- Hurst, Bradley S. (2011). Disorders of menstruation. Chichester, West Sussex: Wiley-Blackwell. ISBN 9781444391817.
- McNamara M, Batur P, DeSapri KT (February 2015). "In the clinic. Perimenopause". Annals of Internal Medicine. 162 (3): ITC1–15. doi:10.7326/AITC201502030. PMID 25643316.
- Kessenich C. "Inevitable Menopause". Archived from the original on 2 November 2013. Retrieved 11 April 2013.
- Bellipanni G, DI Marzo F, Blasi F, Di Marzo A (December 2005). "Effects of melatonin in perimenopausal and menopausal women: our personal experience". Annals of the New York Academy of Sciences. 1057 (1): 393–402. Bibcode:2005NYASA1057..393B. doi:10.1196/annals.1356.030. PMID 16399909.
- The Woman's Health Program Monash University, Oestrogen and Progestin as Hormone Therapy Archived 11 July 2012 at the Wayback Machine
- &Na (March 2010). "Estrogen and progestogen use in postmenopausal women: 2010 position statement of The North American Menopause Society". Menopause. 17 (2): 242–55. doi:10.1097/gme.0b013e3181d0f6b9. PMID 20154637.
- North American Menopause Society (March 2012). "The 2012 hormone therapy position statement of: The North American Menopause Society". Menopause. 19 (3): 257–71. doi:10.1097/GME.0000000000000921. PMC 3443956. PMID 22367731.
- Sarri G, Pedder H, Dias S, Guo Y, Lumsden MA (September 2017). "Vasomotor symptoms resulting from natural menopause: a systematic review and network meta-analysis of treatment effects from the National Institute for Health and Care Excellence guideline on menopause" (PDF). BJOG. 124 (10): 1514–1523. doi:10.1111/1471-0528.14619. PMID 28276200.
- Boardman HM, Hartley L, Eisinga A, Main C, Roqué i Figuls M, Bonfill Cosp X, Gabriel Sanchez R, Knight B (March 2015). "Hormone therapy for preventing cardiovascular disease in post-menopausal women". The Cochrane Database of Systematic Reviews (3): CD002229. doi:10.1002/14651858.CD002229.pub4. PMID 25754617.
- de Villiers TJ, Stevenson JC (June 2012). "The WHI: the effect of hormone replacement therapy on fracture prevention". Climacteric. 15 (3): 263–6. doi:10.3109/13697137.2012.659975. PMID 22612613.
- Marjoribanks J, Farquhar C, Roberts H, Lethaby A, Lee J (January 2017). "Long-term hormone therapy for perimenopausal and postmenopausal women". The Cochrane Database of Systematic Reviews. 1: CD004143. doi:10.1002/14651858.CD004143.pub5. PMC 6465148. PMID 28093732.
- Chlebowski RT, Anderson GL (April 2015). "Menopausal hormone therapy and breast cancer mortality: clinical implications". Therapeutic Advances in Drug Safety. 6 (2): 45–56. doi:10.1177/2042098614568300. PMC 4406918. PMID 25922653.
- Somboonporn W, Davis S, Seif MW, Bell R (October 2005). "Testosterone for peri- and postmenopausal women". The Cochrane Database of Systematic Reviews (4): CD004509. doi:10.1002/14651858.CD004509.pub2. PMID 16235365.
- Davis SR, Dinatale I, Rivera-Woll L, Davison S (May 2005). "Postmenopausal hormone therapy: from monkey glands to transdermal patches". The Journal of Endocrinology. 185 (2): 207–22. doi:10.1677/joe.1.05847. PMID 15845914.
- Bevers TB (September 2007). "The STAR trial: evidence for raloxifene as a breast cancer risk reduction agent for postmenopausal women". Journal of the National Comprehensive Cancer Network. 5 (8): 719–24. PMID 17927929.
- Orleans RJ, Li L, Kim MJ, Guo J, Sobhan M, Soule L, Joffe HV (May 2014). "FDA approval of paroxetine for menopausal hot flushes". The New England Journal of Medicine. 370 (19): 1777–9. doi:10.1056/NEJMp1402080. PMID 24806158.
- Hill, D. Ashley; Crider, Mark; Hill, Susan R. (1 December 2016). "Hormone Therapy and Other Treatments for Symptoms of Menopause". American Family Physician. 94 (11): 884–889. ISSN 1532-0650. PMID 27929271.
- Potter, Beth; Schrager, Sarina; Dalby, Jessica; Torell, Emily; Hampton, Adrienne (2018). "Menopause". Primary Care: Clinics in Office Practice. Women’s Health. 45 (4): 625–641. doi:10.1016/j.pop.2018.08.001. ISSN 0095-4543. PMID 30401346.
- van Driel, CM; Stuursma, A; Schroevers, MJ; Mourits, MJ; de Bock, GH (15 March 2018). "Mindfulness, cognitive behavioural and behaviour-based therapy for natural and treatment-induced menopausal symptoms: a systematic review and meta-analysis". BJOG : An International Journal of Obstetrics and Gynaecology. 126 (3): 330–339. doi:10.1111/1471-0528.15153. PMC 6585818. PMID 29542222.
- Goldstein, KM; Shepherd-Banigan, M; Coeytaux, RR; McDuffie, JR; Adam, S; Befus, D; Goode, AP; Kosinski, AS; Masilamani, V; Williams JW, Jr (April 2017). "Use of mindfulness, meditation and relaxation to treat vasomotor symptoms". Climacteric : The Journal of the International Menopause Society. 20 (2): 178–182. doi:10.1080/13697137.2017.1283685. PMID 28286985.
- Hickey, Martha; Szabo, Rebecca A; Hunter, Myra S (23 November 2017). "Non-hormonal treatments for menopausal symptoms". BMJ. 359: j5101. doi:10.1136/bmj.j5101. ISSN 0959-8138. PMID 29170264.
- Moore, Thea R.; Franks, Rachel B.; Fox, Carol (May 2017). "Review of Efficacy of Complementary and Alternative Medicine Treatments for Menopausal Symptoms". Journal of Midwifery & Women's Health. 62 (3): 286–297. doi:10.1111/jmwh.12628. PMID 28561959.
- Grindler, Natalia M.; Santoro, Nanette F. (2015). "Menopause and exercise". Menopause. 22 (12): 1351–1358. doi:10.1097/GME.0000000000000536. ISSN 1072-3714. PMID 26382311.
- Lauche, Romy; Peng, Wenbo; Cramer, Holger (2018). "Yoga for menopausal symptoms—A systematic review and meta-analysis". Maturitas. 109: 13–25. doi:10.1016/j.maturitas.2017.12.005. ISSN 0378-5122. PMID 29452777.
- Nedrow A, Miller J, Walker M, Nygren P, Huffman LH, Nelson HD (July 2006). "Complementary and alternative therapies for the management of menopause-related symptoms: a systematic evidence review". Archives of Internal Medicine. 166 (14): 1453–65. doi:10.1001/archinte.166.14.1453. PMID 16864755.
- Bolaños R, Del Castillo A, Francia J (2010). "Soy isoflavones versus placebo in the treatment of climacteric vasomotor symptoms: systematic review and meta-analysis". Menopause. 17 (3): 660–6. doi:10.1097/gme.0b013e3181cb4fb5. PMID 20464785.
- Lethaby A, Marjoribanks J, Kronenberg F, Roberts H, Eden J, Brown J (December 2013). "Phytoestrogens for menopausal vasomotor symptoms". The Cochrane Database of Systematic Reviews. 12 (12): CD001395. doi:10.1002/14651858.CD001395.pub4. PMID 24323914.
- EFSA Femarelle® and bone mineral density Archived 30 January 2012 at the Wayback Machine Scientific substantiation of a health claim related to "Femarelle®" and "induces bone formation and increases bone mineral density reducing the risk for osteoporosis and other bone disorders" pursuant to Article 14 of the Regulation (EC) No 1924/20061 Scientific Opinion of the Panel on Dietetic Products, Nutrition and Allergies. The EFSA Journal (2008) 785, pp. 1–10]
- Leach MJ, Moore V (September 2012). "Black cohosh (Cimicifuga spp.) for menopausal symptoms". The Cochrane Database of Systematic Reviews. 9 (9): CD007244. doi:10.1002/14651858.CD007244.pub2. PMC 6599854. PMID 22972105.
- Clement YN, Onakpoya I, Hung SK, Ernst E (March 2011). "Effects of herbal and dietary supplements on cognition in menopause: a systematic review". Maturitas. 68 (3): 256–63. doi:10.1016/j.maturitas.2010.12.005. PMID 21237589.
- Johnson, Alisa; Roberts, Lynae; Elkins, Gary (2019). "Complementary and Alternative Medicine for Menopause". Journal of Evidence-Based Integrative Medicine. 24: 2515690X1982938. doi:10.1177/2515690X19829380. ISSN 2515-690X. PMC 6419242. PMID 30868921.
- Dodin S, Blanchet C, Marc I, Ernst E, Wu T, Vaillancourt C, Paquette J, Maunsell E (July 2013). "Acupuncture for menopausal hot flushes". The Cochrane Database of Systematic Reviews. 7 (7): CD007410. doi:10.1002/14651858.CD007410.pub2. PMC 6544807. PMID 23897589.
- Zhu X, Liew Y, Liu ZL (March 2016). "Chinese herbal medicine for menopausal symptoms". The Cochrane Database of Systematic Reviews. 3: CD009023. doi:10.1002/14651858.CD009023.pub2. PMC 4951187. PMID 26976671.
- Wells GA, Cranney A, Peterson J, Boucher M, Shea B, Robinson V, Coyle D, Tugwell P (January 2008). "Alendronate for the primary and secondary prevention of osteoporotic fractures in postmenopausal women". The Cochrane Database of Systematic Reviews (1): CD001155. doi:10.1002/14651858.CD001155.pub2. PMID 18253985.
- "Concerns over new 'menopause delay' procedure". BBC News. 28 January 2020.
- Moore AM (2018). "Conceptual Layers in the Invention of Menopause in Nineteenth-Century France". French History. 32 (2): 226–248. doi:10.1093/fh/cry006.
- Winterich, J. (August 2008). "Gender, medicine, and the menopausal body: How biology and culture influence women's experiences with menopause". Paper presented at the annual meeting of the American Sociological Association, New York. Retrieved 11 November 2008 from Allacademic.com Archived 9 July 2012 at the Wayback Machine
- Gannon L, Ekstrom B (1993). "Attitudes toward menopause: The influence of sociocultural paradigms". Psychology of Women Quarterly. 17 (3): 275–88. doi:10.1111/j.1471-6402.1993.tb00487.x. hdl:2286/R.I.44298.
- Avis N, Stellato RC, Bromberger J, Gan P, Cain V, Kagawa-Singer M (2001). "Is there a menopausal syndrome? Menopausal status and symptoms across racial/ethnic group". Social Science & Medicine. 52 (3): 345–56. doi:10.1016/S0277-9536(00)00147-7. PMID 11330770.
- Lock M (1998). "Menopause: lessons from anthropology". Psychosomatic Medicine. 60 (4): 410–9. doi:10.1097/00006842-199807000-00005. PMID 9710286.
- Melby MK (2005). "Factor analysis of climacteric symptoms in Japan". Maturitas. 52 (3–4): 205–22. doi:10.1016/j.maturitas.2005.02.002. PMID 16154301.
- Lock, M. & Nguyen, V. (2010) An Anthropology of Biomedicine, Chapter 4 "Local Biologies and Human Difference" (pp. 84–89), West Sussex, Wiley-Blackwell
- Gold EB, Block G, Crawford S, Lachance L, FitzGerald G, Miracle H, Sherman S (June 2004). "Lifestyle and demographic factors in relation to vasomotor symptoms: baseline results from the Study of Women's Health Across the Nation". American Journal of Epidemiology. 159 (12): 1189–99. doi:10.1093/aje/kwh168. PMID 15191936.
- Maoz B, Dowty N, Antonovsky A, Wisjenbeck H (1970). "Female attitudes to menopause". Social Psychiatry. 5: 35–40. doi:10.1007/BF01539794.
- Stotland NL (August 2002). "Menopause: social expectations, women's realities". Archives of Women's Mental Health. 5 (1): 5–8. doi:10.1007/s007370200016. PMID 12503068.
- Walker ML, Herndon JG (September 2008). "Menopause in nonhuman primates?". Biology of Reproduction. 79 (3): 398–406. doi:10.1095/biolreprod.108.068536. PMC 2553520. PMID 18495681.
- Ben Guarino (27 August 2018). "Beluga Whales and Narwhals Go Through the Menopause Too". Retrieved 24 November 2019.
- Gaulin SJ (1980). "Sexual Dimorphism in the Human Post-reproductive Life-span: Possible Causes". Journal of Human Evolution. 9 (3): 227–32. doi:10.1016/0047-2484(80)90024-X.
- Holmberg, I. (1970), "Fecundity, Fertility and Family Planning". Demography Institute University of Gothenburg Reports. 10: pp. 1–109
- Washburn, S.L. (1981). "Longevity in Primates". In: Aging: Biology and Behavior by McGaugh, J.L. and S. B. Kiesler, S.B. (eds). pp. 11–29. Academic Press.
- Hawkes K (March 2004). "Human longevity: the grandmother effect". Nature. 428 (6979): 128–9. Bibcode:2004Natur.428..128H. doi:10.1038/428128a. PMID 15014476.
- Ricklefs RE, Wikelski M (2002). "The Physiology/Life-history Nexus". Trends in Ecology & Evolution. 17 (10): 462–68. doi:10.1016/S0169-5347(02)02578-8.
- "How Women Got Their Curves and Other Just-So Stories: Evolutionary Enigmas", David Barash, David P. Barash, Judith Eve Lipton 2010
- "The Arc of Life: Evolution and Health Across the Life Course", Grazyna Jasienska, Diana S. Sherry, Donna J. Holmes 2017
- Darwin C. Origin of Species. Archived from the original on 3 October 2013. Retrieved 24 September 2013.
- "A View to a Kill: Investigating Middle Palaeolithic Subsistence Using an Optimal Foraging perspective", Gerrit Leendert Dusseldorp 2009
- "The Journey of Adulthood", Helen L. Bee, Barbara R. Bjorklund 2003
- Morton RA, Stone JR, Singh RS (13 June 2013). "Mate choice and the origin of menopause". PLoS Computational Biology. 9 (6): e1003092. Bibcode:2013PLSCB...9E3092M. doi:10.1371/journal.pcbi.1003092. PMC 3681637. PMID 23785268.
- Takahashi M, Singh RS, Stone J (6 January 2017). "A Theory for the Origin of Human Menopause". Frontiers in Genetics. 7: 222. doi:10.3389/fgene.2016.00222. PMC 5216033. PMID 28111590.
- Johnstone RA, Cant MA (December 2010). "The evolution of menopause in cetaceans and humans: the role of demography". Proceedings. Biological Sciences. 277 (1701): 3765–71. doi:10.1098/rspb.2010.0988. PMC 2992708. PMID 20591868.
- Lawson Handley LJ, Perrin N (April 2007). "Advances in our understanding of mammalian sex-biased dispersal". Molecular Ecology. 16 (8): 1559–78. doi:10.1111/j.1365-294x.2006.03152.x. PMID 17402974.
- Ségurel L, Martínez-Cruz B, Quintana-Murci L, Balaresque P, Georges M, Hegay T, Aldashev A, Nasyrova F, Jobling MA, Heyer E, Vitalis R (September 2008). "Sex-specific genetic structure and social organization in Central Asia: insights from a multi-locus study". PLoS Genetics. 4 (9): e1000200. doi:10.1371/journal.pgen.1000200. PMC 2535577. PMID 18818760.
- Sugiyama Y (July 2017). "Sex-biased dispersal of human ancestors". Evolutionary Anthropology. 26 (4): 172–180. doi:10.1002/evan.21539. PMID 28815964.
- Bigg MA, Olesiuk PF, Ellis GM, Ford JK, Balcomb KC (1 January 1990). "Social organization and genealogy of resident killer whales (Orcinus orca) in the coastal waters of British Columbia and Washington State". Report of the International Whaling Commission. 12: 383–405.
- Croft DP, Johnstone RA, Ellis S, Nattrass S, Franks DW, Brent LJ, Mazzi S, Balcomb KC, Ford JK, Cant MA (January 2017). "Reproductive Conflict and the Evolution of Menopause in Killer Whales". Current Biology. 27 (2): 298–304. doi:10.1016/j.cub.2016.12.015. PMID 28089514.
- Heimlich-Boran JR (1993). Social organisation of the short-finned pilot whale, Globicephala macrorhynchus, with special reference to the comparative social ecology of delphinids (Doctoral thesis). University of Cambridge.
- Peccei JS (2001). "Menopause: Adaptation or Epiphenomenon?". Evolutionary Anthropology. 10 (2): 43–57. doi:10.1002/evan.1013.
- Lahdenperä M, Lummaa V, Helle S, Tremblay M, Russell AF (March 2004). "Fitness benefits of prolonged post-reproductive lifespan in women" (PDF). Nature. 428 (6979): 178–81. Bibcode:2004Natur.428..178L. doi:10.1038/nature02367. PMID 15014499.
- Voland, E. and Beise, J. (2002). "Opposite Effects of Maternal and Paternal Grandmothers on Infant Survival in Historical Krummörn". MPIDR WP 2001–026.
- Mace, R and Sear, R. (2004). "Are Humans Communal Breeders?" In: Voland, E., Chasiotis, A. and Schiefenhoevel, W. (eds). Grandmotherhood – the Evolutionary Significance of the Second Half of Female Life. Rutgers University Press.
- Peccei JS (2001). "A critique of the grandmother hypotheses: old and new". American Journal of Human Biology. 13 (4): 434–52. doi:10.1002/ajhb.1076. PMID 11400215.
- "Engels was Right: Early Human Kinship was Matrilineal". Archived from the original on 27 February 2014.
- 10. Finch, C.E. 1990. Longevity senescence and the genome. University of Chicago Press. London.
- Pavard S, Sibert A, Heyer E (May 2007). "The effect of maternal care on child survival: a demographic, genetic, and evolutionary perspective". Evolution; International Journal of Organic Evolution. 61 (5): 1153–61. doi:10.1111/j.1558-5646.2007.00086.x. PMID 17492968.
- Walker RS, Flinn MV, Hill KR (November 2010). "Evolutionary history of partible paternity in lowland South America". Proceedings of the National Academy of Sciences of the United States of America. 107 (45): 19195–200. Bibcode:2010PNAS..10719195W. doi:10.1073/pnas.1002598107. PMC 2984172. PMID 20974947.
- Massart F, Reginster JY, Brandi ML (November 2001). "Genetics of menopause-associated diseases". Maturitas. 40 (2): 103–16. doi:10.1016/S0378-5122(01)00283-3. PMID 11716989.
- Leidy, L. "Menopause in evolutionary perspective". in: Trevathan WR, McKenna JJ, Smith EO (Eds.) Evolutionary Medicine. Oxford University Press, pp. 407–27
- Clinical Obstetrics and Gynaecology (3 ed.). Elsevier Health Sciences. 2014. p. 69. ISBN 9780702054105.
- Clutton-Brock TH, Hodge SJ, Spong G, Russell AF, Jordan NR, Bennett NC, Sharpe LL, Manser MB (December 2006). "Intrasexual competition and sexual selection in cooperative mammals". Nature. 444 (7122): 1065–8. Bibcode:2006Natur.444.1065C. doi:10.1038/nature05386. PMID 17183322.
- Lahdenperä M, Gillespie DO, Lummaa V, Russell AF (November 2012). "Severe intergenerational reproductive conflict and the evolution of menopause". Ecology Letters. 15 (11): 1283–1290. doi:10.1111/j.1461-0248.2012.01851.x. PMID 22913671.
- Jaeggi AV, Gurven M (July 2013). "Natural cooperators: food sharing in humans and other primates". Evolutionary Anthropology. 22 (4): 186–95. doi:10.1002/evan.21364. PMID 23943272.
- Cant MA, Johnstone RA (April 2008). "Reproductive conflict and the separation of reproductive generations in humans". Proceedings of the National Academy of Sciences of the United States of America. 105 (14): 5332–6. Bibcode:2008PNAS..105.5332C. doi:10.1073/pnas.0711911105. PMC 2291103. PMID 18378891.
- Wright BM, Stredulinsky EH, Ellis GM, Ford JK (May 2016). "Kin-directed food sharing promotes lifetime natal philopatry of both sexes in a population of fish-eating killer whales, Orcinus orca". Animal Behaviour. 115: 81–95. doi:10.1016/j.anbehav.2016.02.025.
- Walker ML (1995). "Menopause in female rhesus monkeys". Am J Primatol. 35: 59–71. doi:10.1002/ajp.1350350106.
- Bowden, D. M. and Williams, D. D. (1985). Aging. Adv.Vet.Sci.Comp.Med. 28: 306–41
- Sukumar, R. (1992). The Asian Elephant. ISBN 9780521437585. Archived from the original on 12 May 2016.
- Marsh, H and Kasuya, T. (1986). Evidence for Reproductive Senescence in Female Cetaceans. Report of the International Whaling Commission. 8: pp. 57–74.
- Brent LJ, Franks DW, Foster EA, Balcomb KC, Cant MA, Croft DP (March 2015). "Ecological knowledge, leadership, and the evolution of menopause in killer whales". Current Biology. 25 (6): 746–750. doi:10.1016/j.cub.2015.01.037. PMID 25754636.
- Ellis S, Franks DW, Nattrass S, Currie TE, Cant MA, Giles D, Balcomb KC, Croft DP (August 2018). "Analyses of ovarian activity reveal repeated evolution of post-reproductive lifespans in toothed whales". Scientific Reports. 8 (1): 12833. Bibcode:2018NatSR...812833E. doi:10.1038/s41598-018-31047-8. PMC 6110730. PMID 30150784.
- Reznick D, Bryant M, Holmes D (January 2006). "The evolution of senescence and post-reproductive lifespan in guppies (Poecilia reticulata)". PLoS Biology. 4 (1): e7. doi:10.1371/journal.pbio.0040007. PMC 1318473. PMID 16363919.
- Canine reproduction
- "How long is a cat in heat?". Animal Planet. 15 May 2012. Retrieved 12 June 2018.
|Wikimedia Commons has media related to Menopause.|