Pressing Pause on Your Fertility: Contraception via Egg Hibernation
Post written by Tishina Okegbe, FHI 360
Women currently have several methods of reversible contraception to choose from, including hormonal options such as the implant, injectables and pills, and nonhormonal options such as the condom and the copper intrauterine device. Though this is true, there are some 214 million women in lower-and middle-income countries who want to avoid or delay pregnancy, yet who are not using a modern form of contraception. Further, nearly one-third of women in these regions who have used a modern method of contraception chose to discontinue use within one year. Many reasons are cited for discontinuation of contraception, including convenience, side effects and cost. Well, what if there were an easier way for women to contracept?
Novel research from David Pépin’s lab, published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) in 2017 shed some insight on a newly uncovered biological mechanism that may serve women as both a contraceptive and a fertoprotective – protecting against the depletion of ovarian reserves due to chemotherapy and radiation.
The protein, Müllerian inhibiting substance/anti-Müllerian hormone (MIS/AMH), is critical for proper reproductive tract development in both males and females; however, in females, it also acts to activate ovarian follicles during adulthood. Women are born with ~1 million ovarian follicles that later develop into eggs. By the time a girl enters puberty, she will have ~300,000 eggs in her ovarian reserve, only about 25% of her lifetime total egg pool. As she nears her late 30’s, most women experience a significant decrease in fertility, until all eggs have been depleted at the conclusion of menopause.
The findings from the Pépin lab show that by overexpressing MIS/AMH in mice, follicle maturation is halted, leaving a reservoir of immature follicles. Further, the researchers did not discover any adverse effects on the mice, as the MIS/AMH receptor is localized to the reservoir of follicles. This technology is exciting. Just imagine: there could be an opportunity for immature eggs to “hibernate,” only awakening when a woman is ready to conceive a child. It is worth noting that research is still preliminary, and it is unclear whether follicles induced into hibernation produce viable eggs. However, given this promising mechanism, perhaps in 20 or 30 years our daughters can press “pause” on their fertility, until they desire children.