What If You Get Pregnant During Perimenopause?

I am 43 and believe I was experiencing some symptoms of a pre-perimenopausal trajectory (night wakes, more irregular periods) when I became pregnant. Immediately all those symptoms stopped, and now I am on the pregnancy and postpartum hormonal train. What happens when I finally am no longer pregnant or breastfeeding around age 46-47? Do I start pre-perimenopause again where I left off, or will I land in a later stage where I would have been had I not become pregnant?
—BostonMom

Congratulations on your pregnancy! It certainly would make sense that if you were having perimenopausal symptoms before pregnancy, they would immediately evaporate the minute you got pregnant. Estrogen increases as much as 10-fold in the first trimester of pregnancy and remains stable and high throughout pregnancy.

Hot flushes, night sweats, and many other perimenopausal symptoms are the body’s response to dropping estrogen. So pregnancy would be a great treatment for those symptoms.

couple expecting a baby — Amina Filkins / Pexels

In the postpartum period, all women have a significant drop in estrogen levels. Estrogen levels return to prepregnancy levels by about five days postpartum. This is why many women experience hot flushes and night sweats in the early postpartum period. In your case, I would not interpret these symptoms as suggestive of perimenopause.

During breastfeeding, the hormone prolactin and later the act of suckling itself often suppresses the production of follicle-stimulating hormone and luteinizing hormone, which are responsible for stimulating egg maturation and triggering ovulation. As a result, some women won’t resume having regular periods until they wean.

There is no data to tell us what will happen when you wean. Many researchers have looked for associations between age at last pregnancy and age at menopause, and there is conflicting evidence, with some studies suggesting that giving birth after 40 is associated with older age at menopause and other studies suggesting the opposite.

The good news is that when you do wean, you can watch for the symptoms you were having pre-pregnancy. If they recur and they are affecting your functioning, you can be prepared to reach out to your doctor right away.