If you’re a woman in your 30s, not getting your period is often a sign that you might be pregnant. But it could also be an indicator of menopause. Yes, you read that right: menopause.
What used to be called premature menopause is now known by the medical term primary ovarian insufficiency (POI), which indicates that the ovaries are not functioning normally in a woman under the age of 40.
POI isn’t completely synonymous with menopause because the ovaries haven’t totally shut down, and the woman may still get her period. The body’s production of the reproductive hormones (including estrogen and progesterone) may still occur sporadically, and eggs can still be released from the ovaries. As a result, the woman still could become pregnant (as can any woman in the years leading up to menopause), though it’s not likely.
POI is sometimes called “early menopause,” but the latter term is generally used more broadly to include women up to age 45. POI applies specifically to women younger than 40.
Approximately 1 to 2 percent of all women worldwide experience natural menopause before the age of 40, according to the European Society of Human Reproduction and Embryology. And some evidence suggests the condition is underdiagnosed.
In addition to infrequent or missed periods, POI can cause symptoms typically associated with menopause, including hot flashes, vaginal dryness, and eventually, pain during sexual intercourse due to the thinning of the vaginal walls. About three-quarters of women with POI experience such symptoms, which may vary in severity and come on intermittently or rarely as estrogen levels fluctuate. In contrast, women who develop premature menopause due to cancer treatment or having their ovaries surgically removed tend to have more severe and longer-lasting symptoms, perhaps because their estrogen leveldrops more rapidly than in women going through natural menopause.
Much of the time, no known cause of POI can be determined. In some cases (estimates vary from 4 percent to 30 percent), it stems from an autoimmune problem. Genetic abnormalities may also play a role; indeed, between 15 and 30 percent of women who develop POI have a family history of premature menopause. Other risk factors include getting your first period at age 11 or younger, especially if you have never been pregnant, according to an observational study of more than 50,000 women in several countries published in 2017 in Human Reproduction.
A diagnosis of POI is usually based on missed or infrequent periods for at least four months and abnormal levels of a hormone called FSH (follicle stimulating hormone) on two separate tests at least a month apart. Other blood tests may also be done to rule out other causes.
Risks of POI
Entering menopause before age 40 is associated with two major long-term health risks: osteoporosis and cardiovascular disease, though much of the evidence comes from studies in women with surgical menopause due to the removal of both ovaries—so it’s not always clear whether the same risks apply to POI that occurs naturally or from other causes, such as chemotherapy. In a large study that looked at women who developed POI for no apparent reason, at an average age of 32, researchers found that they had lower bone mineral density compared to controls who were still menstruating. And other research has shown that women who have POI for various reasons (natural or induced by chemotherapy or surgery) have higher rates of bone loss and a greater risk of bone fractures.
Women with POI also have a higher rate of premature death compared with women who enter menopause at a more typical time (the average age is 51). Many, though not all, studies have found that women who enter menopause early—before age 40 in some studies, before 45in others—have a higher risk of heart disease and death due to cardiovascular disease, and possibly a higher risk of stroke. That's all presumably due to the decline in estrogen, which is heart-protective. And an observational study published in July 2017 in Diabetologia found that women with early-onset menopause (as well as those who enter menopause at the normal age) are at higher risk of developing type 2 diabetes than those with late-onset menopause.
On the flip side, earlier menopause is linked with a lower risk of breast cancer. According to one meta-analysis of data from nearly 119,000 women, the risk of the cancer increased for every year younger at the onset of menstruation and every year older at menopause. Put another way, premenopausal women had a greater risk of breast cancer than postmenopausal women of the same age.
Guidelines from the European Society of Human Reproduction and Embryology, as well as many of the published studies on POI that we found, recommend that women with POI begin estrogen therapy (along with progestin, a form of progesterone), not only to deal with menopausal symptoms such as night sweats but also to offset the potential health risks discussed above. The woman should continue hormone therapy until age 50, then gradually taper off. Women for whom estrogen is contraindicated, such as those with a history of breast cancer, should not take hormones to treat POI. (Note that the use of hormone replacement therapy remains controversial in older women—mainly those in their 60s—since it’s been linked to an increased risk of breast cancer, heart attacks, and strokes in that age group.)
Bottom line: If you are younger than 40 and experiencing irregular or missed periods, make an appointment with your gynecologist, who will talk with you about your family history and the history of your menstrual cycle, do a physical exam, and take blood tests to determine the cause. If it turns out you have POI, talk with the doctor about the pros and cons of starting hormone replacement therapy. In addition, take other steps to help prevent bone loss, including not smoking, getting adequate calcium and vitamin D, and doing weight-bearing exercise.
Also see Perimenopause: A Time for Change.