Can You Get Pregnant During Perimenopause? Exploring Fertility Changes
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While your fertility naturally declines as you age, people often wonder at what point it’s no longer possible to conceive. As with everything during perimenopause and menopause, the answer can vary widely from person to person, but it’s important to know that yes, you can get pregnant during perimenopause. And what’s more, there’s a phase of perimenopause when your risk of becoming pregnant with twins increases.
“If you’re sexually active with a male partner and don’t want to get pregnant, then birth control is really imperative while you’re in your 40s,” says Dr. Heidi Snyder Flagg, an OB/GYN and Flow Advisory Council member. Here’s what to know about how your fertility changes during perimenopause.
While people often refer to menopause as the time when women and menstruating people experience age-related changes in their reproductive health, it actually refers to a point in time one year after your final period. Everything leading up to that point is perimenopause.
“Menopause is the endgame of this whole process,” says Dr. Flagg. “We really have no ability to predict when a woman will actually cross the divide from perimenopause and menopause.” There’s a wide range for when this can occur — perimenopause can start in your 30s and extend into your late 50s — though the average age of menopause is 51 and a half years.
To understand the chance of a pregnancy occurring during perimenopause, it’s helpful to consider the two phases of perimenopause. If you’re someone with a regular cycle, the early phase of perimenopause (also known as the LOOP phase) is when you’ll start to see irregular periods, as changes in ovary function translate to fluctuations in your hormones.
It can help to think of this phase as “hyperdrive,” says Dr. Flagg. During the first phase of perimenopause, you might actually bleed more and your periods can come closer together. There can be a surge of hormones flooding your system during perimenopause, in comparison to menopause, when estrogen levels are very low. “I describe it to my patients as a rollercoaster ride where estrogen is coming up and then crashing down.”
Estrogen is produced by the ovaries, but over time a drop in egg numbers affects how much estrogen is made in the body. “It’s this process of losing your eggs and estrogen source that drives the perimenopause and menopause process,” Dr. Flagg says. In fact, as a fetus, you can have up to 6 million eggs, a number that drops to 2 million when you’re born and to 300,000 by puberty. Reaching your late 30s lowers the egg count to 25,000 eggs and eventually to three or four hundred during menopause.
The hormone fluctuations of perimenopause can cause you to ovulate multiple times (instead of once) in a single cycle. “You are actually hyperovulating,” explains Dr. Flagg. “You are not just ovulating one egg — you ovulate multiple times in one cycle.” Releasing multiple eggs in a single cycle can increase the chances of becoming pregnant with twins. If you’re not trying to have a child, this is when it’s key to have a conversation with your health care provider about birth control. “This is always a good time to discuss with my patients who are usually 40 to 44 and sexually active with a male partner, that if they don’t want to get pregnant, birth control is really important.”
Keep in mind that just because hyperovulation can occur during perimenopause doesn’t mean you’ll become pregnant more easily. Egg age is a critical factor for achieving pregnancy and by your 40s and 50s, the odds of pregnancy are much lower. “The chance of a 52- or 55-year-old becoming naturally pregnant is as probably close to zero as we are going to get,” explains Dr. Flagg. “The genetic material in that egg is probably not going to be compatible with fully forming a baby.”
Advanced age can make it difficult for the body to support a growing fetus, Dr. Flagg adds. The circulatory system is not as healthy as it is in your twenties, for example, and blood flow changes can contribute to high-risk pregnancy with conditions such as preeclampsia.
The bottom line is pregnancy is possible during perimenopause. And if you’re trying to avoid a surprise pregnancy (or twins), then talk to your healthcare provider to find the birth control method that’s right for you.