The average age for a woman to reach menopause is about 51. A woman has reached menopause when she has had no menstrual periods for 12 months. The transition between the reproductive years and menopause is gradual and can last for several years. Doctors call this phase perimenopause. Periods become more irregular, and other symptoms like night sweats, hot flashes, mood changes, changes in sexuality may become bothersome.
What Causes Menopause
Very simply, a woman reaches menopause when she runs out of functioning eggs. The journey toward menopause actually begins before birth! At 24 weeks of pregnancy, a baby girl’s ovaries contain several million eggs. From that point, eggs degenerate naturally and very rapidly. By the time she is born, this baby has already lost about 80% of her supply. At puberty, her supply has fallen to a few hundred thousand—still plenty for her future fertility. The process continues throughout her reproductive life.
Each month, one egg matures inside its little sac (follicle) within the ovary and is released (ovulation). But for every ovulation of a mature egg, about 1000 others just disintegrate. Eventually no more functioning eggs are left, and periods stop. Without maturing follicles, the ovary is no longer producing estrogen. Because estrogen plays a role in many body functions, women experience a wide range of symptoms when it dwindles.
Menopause is usually a natural aging process, but surgery to remove the ovaries will result in menopause. Chemotherapy and/or radiation treatment can cause a temporary or permanent end of menstrual periods. A woman whose periods end before age 40 is said to have early or premature menopause. Premature menopause occurs for about 1% of American women. The physician will not always be able to identify the cause for an individual woman. Genetic, metabolic, and auto-immune problems can explain some, but not all, of these cases.
The Health Effects of Early Menopause
Early menopause brings great emotional distress for a woman who desires a future pregnancy. A woman whose periods have stopped before age 40 is very unlikely to have a spontaneous pregnancy. However, women who do not wish to become pregnant need to be counselled about how long to continue using birth control.
Besides loss of fertility, premature menopause has other adverse effects on a woman’s future health. Without estrogen, the risk of cardiovascular disease and osteoporosis (weakening of bones) rises sharply. Women experience uncomfortable symptoms like hot flashes, urinary problems, thinning and dryness of vaginal tissues, changes in mood, sleep, and mental focus. Premature menopause places a serious burden on a woman’s feelings of well-being and overall quality of life.
Hormone Replacement Therapy
Regardless of the cause of premature menopause, we recommend hormone treatment to protect against heart disease and osteoporosis, and also to maintain a woman’s overall quality of life. Unless estrogen therapy poses a serious specific risk for an individual woman, we rely on full hormone replacement at least until she reaches average menopausal age. In some cases, we may prescribe estrogen even for a woman with risk factors, for example, higher risk of breast cancer. We want to help each woman weigh the risks and benefits of her treatment options. We encourage her to continue estrogen therapy beyond normal menopausal age if symptoms are still interfering with quality of life. A woman who has had breast cancer or a blood clot is usually not able to take hormone replacement.
The risk of premature menopause is greater for a woman who has a significant family history of premature menopause (mother, sister). Consulting her ob-gyn early will give her an opportunity to consider freezing eggs for a future in vitro pregnancy.
You should not think of early menopause as just a variation of normal aging. Any woman under 40 who usually has regular periods, regardless of her age, should see her doctor if she misses 3 periods and sooner if pregnancy is possible. Likewise, if she begins to notice menopausal symptoms like hot flashes or vaginal dryness, she should make an appointment to see her ob-gyn. A woman diagnosed with premature menopause faces difficult physical and emotional challenges. We want to help her understand her condition, and offer both medical treatment and emotional support.