A large study of pregnancy outcomes reveals that women exposed to semaglutide (a GLP-1 receptor agonist used in weight loss and diabetes treatment) before and during pregnancy experienced significantly higher rates of pregnancy complications compared to those who never used the drug. The research, published in Obstetrics and Gynecology, examined over 3,400 women with overweight or obesity who delivered between January 2022 and January 2026, offering new insights into how these increasingly popular medications affect reproductive health.

What Pregnancy Complications Did Researchers Find?

Researchers led by Yang Yu, PhD, MPH, MNS, an assistant professor at the University of Rochester School of Nursing, compared three groups of women: those who used semaglutide before and into pregnancy, those who stopped before pregnancy, and those who never used it. The findings were striking. Women who continued semaglutide into pregnancy experienced an average of 5.12 kilograms (about 11 pounds) more gestational weight gain than nonusers. They also faced substantially elevated risks across multiple complications.

• Gestational Diabetes Risk: Pregnancy-exposed users were 59% more likely to develop gestational diabetes, a condition where blood sugar levels become elevated during pregnancy and can affect both mother and baby.
• Excessive Fetal Growth: Babies of semaglutide-exposed mothers were 78% more likely to grow excessively in the womb, which can complicate delivery and newborn health.
• Cesarean Delivery: Women exposed to semaglutide during pregnancy were more than three times as likely to require a cesarean section, compared to nonusers.

Interestingly, women who stopped semaglutide before pregnancy also faced elevated risks, though the study found no statistically significant differences between those who continued the drug and those who discontinued it beforehand. About one-third of women who used semaglutide before pregnancy were also exposed to it after conception, with a median exposure of 44 days.

Why Does Weight Rebound After Stopping the Drug Matter?

The research points to a surprising culprit: rapid weight regain after stopping semaglutide, rather than the drug itself reaching the baby. Current drug labeling advises women to discontinue semaglutide at least two months before attempting to conceive, based on animal studies linking pregnancy exposure to miscarriage and birth defects. However, the new findings suggest the real problem may be what happens when women stop taking the medication.

"One important mechanism may be weight rebound after semaglutide discontinuation. Excessive gestational weight gain is a well-established risk factor for a range of adverse pregnancy outcomes, and women who stop semaglutide often experience rapid weight regain," said Yang Yu, PhD, MPH, MNS.

Yang Yu, PhD, MPH, MNS, Assistant Professor at University of Rochester School of Nursing

This weight rebound hypothesis is supported by international research. Henriette Svarre Nielsen, MD, DMSc, chair and professor of obstetrics and gynecology at the University of Copenhagen, noted that both American and Danish real-world studies point in the same direction: the risks appear linked to metabolic changes after discontinuation, not to the drug's direct effects on the developing fetus.

What Should Women Planning Pregnancy Know?

The study raises important questions about how to manage the transition off semaglutide for women who want to become pregnant. Approximately 40% of pregnancies in the United States are unplanned, and strict contraceptive use is not mandated during GLP-1 treatment. Additionally, these drugs may enhance fertility through weight loss and metabolic improvements, creating a paradox where women become more likely to conceive while taking medications they're advised to stop before pregnancy.

Experts emphasize that women need reassurance, not alarm, if they discover they're pregnant while using semaglutide. The current recommendation remains to follow the minimum two-month cessation period before attempting conception, based on the drug's long half-life and clearance time from the body. However, researchers stress that more evidence is needed to determine the optimal timing for discontinuation.

"Women who conceive unexpectedly need reassurance, not alarm," noted Henriette Svarre Nielsen, MD, DMSc.

Henriette Svarre Nielsen, MD, DMSc, Chair and Professor of Obstetrics and Gynecology at University of Copenhagen

How to Navigate GLP-1 Use and Pregnancy Planning

• Use Effective Contraception: Because GLP-1 drugs may boost fertility through weight loss and metabolic improvements, reliable contraception is critical if you're not ready to become pregnant. Keep in mind that gastrointestinal side effects like vomiting may reduce the effectiveness of oral contraceptives.
• Consult Your Healthcare Team: If you're taking semaglutide for diabetes treatment and planning pregnancy, discuss the potential risks and benefits with your doctor. The decision to continue, modify, or discontinue treatment should be made collaboratively based on your individual health situation.
• Plan Ahead for Discontinuation: If you're using semaglutide for weight loss and want to become pregnant, work with your healthcare provider to plan a discontinuation strategy that minimizes rapid weight regain, which appears to be a key driver of pregnancy complications.
• Seek Reassurance if Unexpectedly Pregnant: If you discover you're pregnant while taking semaglutide, contact your healthcare provider immediately. Unintended exposure during early pregnancy does not automatically mean serious harm, but medical guidance is important.

The study involved 429 women who used semaglutide during pregnancy, 801 who stopped before pregnancy, and 2,203 who never used the drug. The research was supported by the Heilbrunn Family Center for Research Nursing at Rockefeller University and represents one of the largest real-world examinations of how these increasingly popular weight loss medications affect pregnancy outcomes.

As GLP-1 use continues to expand among reproductive-age women, researchers emphasize the need for further investigation into the biological mechanisms linking semaglutide use and discontinuation to pregnancy outcomes, potential effects on long-term child health, and the risk of birth defects in larger human studies. Understanding how to safely manage these medications during the reproductive years remains an urgent priority for women's health.