It’s a question many women wonder about, especially if you’re thinking about planning a family and your 20s are but a distant memory.
How many more years of fertility might you have, and how much longer will it be before you start experiencing “the change?”
Here's what does -- and does not influence the age at when a woman reaches menopause.
The Top Factor
There are a number of factors that affect a woman’s age at menopause, but one is more important than any other: the age her mother experienced menopause.
“Menopause is strongly genetically linked, so you’re very likely to fall within a few years either way of the age your mother was at menopause,” says Nanette Santoro, MD, director of the division of reproductive endocrinology and infertility at the University of Colorado-Denver School of Medicine and a member of the board of directors of the American Society for Reproductive Medicine.
This isn’t always true, of course. Some women reach menopause at an unusually early age -- before 45 or so -- with no known cause, which could be the result of an inherited issue or a one-time genetic mutation. “These can be random events, but can also be passed on," says Howard Zacur, MD, PhD, who directs the reproductive endocrinology and infertility division at Johns Hopkins School of Medicine.
So if your mother reached menopause at 40, but her sisters and your grandmother were all around the average age of 50, it’s unclear whether you’ll follow her path or theirs.
But if most of the women in your family, your mother included, reach menopause early, late, or somewhere in the middle, you can eye your calendar with some degree of confidence.
Menopause Age: 4 More Influences
Your mother's age at menopause is a key factor, but not the only one. Here are four others to consider:
- Smoking . No other lifestyle factor does more damage to your ovaries than smoking. So if you smoke and your mother didn’t, you’ll probably reach menopause earlier than she did. If she smoked and you don’t, you probably reach menopause later than she did.
- Chemotherapy . Most forms of chemotherapy used in younger women are at least mildly toxic to the ovaries. Many women go through temporary menopause while undergoing chemotherapy; if cycles do return (they don’t always), you can still expect to reach regular menopause a couple of years earlier than you otherwise would have.
- Ovarian surgery. “The more you operate on the ovaries, the more healthy tissue gets damaged,” says Marcelle Cedars, MD, director of the division of reproductive endocrinology at the University of California, San Francisco, School of Medicine. So if you’ve had diagnostic surgery for endometriosis, for example, Cedars recommends using medical options (such as hormonal suppression) to treat the condition in order to avoid repetitive surgeries.
- Ethnicity. “Certain ethnic groups may have menopause at slightly different ages,” says Santoro. “Hispanic and African-American women reach menopause a little earlier, and Chinese and Japanese women a little later, than the average Caucasian woman, who reaches menopause at about age 51.5.” Those are averages; every woman is different.
Not a Factor
Here are three things you might think would influence menopause age, but don’t:
- Age at first period. Although the average age of menarche (onset of first menstrual period) has been getting younger in U.S. women, there hasn’t been a corresponding shift in the average age at menopause. The average age at menarche is now about 12.4 years old, down from 13.3 in women born prior to the 1920s, but the average age at menopause has been around 51.5 for decades. “You would assume that a woman only has so many cycles in her life and if she menstruates later, she’ll reach menopause later, but that doesn’t seem to be true,” Cedars says.
- Pregnancy and breastfeeding. These have no impact on menopause age.
- Use of hormonal birth control methods. “Even if you’re using a birth control method that stops ovulation, it doesn’t stop the loss of follicles, the constant process of the ovary taking them from the resting pool of eggs,” Cedars says. “All the follicles available in the cohort that month die away, even if you’re not ovulating, so birth control doesn’t appear to delay menopause."
There is no way to delay menopause; it can only be sped up, not slowed down, by external factors.
And there are some factors that are still unknowns. For instance, researchers are studying bisphenol A (BPA), a chemical used to make certain plastics, in relation to various cancers as well as the reproductive system and metabolic processes.
Could BPA exposure influence age at menopause? “My guess would be no, since the age of menopause hasn’t changed much over the years as we’ve been exposed to more of these environmental toxins, but research will be exploring the role of substances like BPA in ovarian function,” Santoro says.
Predicting Menopause Age
Other than avoiding smoking, there’s probably not much you can do to influence the age at which you’ll reach menopause. But as you get closer to that time, it will be easier to predict more accurately when it will happen.
"If you’re over the age of 45 and skip at least three periods in a row, that tells us that you’re going to move on to menopause relatively soon," Santoro says. “But we’re still working on blood tests to see if we can predict this more accurately.”