Planning a pregnancy? New guidelines on weight loss medications

The use of weight loss medications such as Ozempic, Wegovy, and Mounjaro continues to rise worldwide. However, for women of reproductive age, this raises complex questions: Does treatment affect fertility? Can it be continued during pregnancy? And what happens if a woman discovers she is pregnant while taking the medication? A new international consensus document, along with a systematic review in the journal Obesity Reviews, attempts to bring clarity to these issues.

Why treat obesity before pregnancy?

Experts emphasize that obesity affects not only weight but also fertility and the course of pregnancy. Women with obesity are at higher risk for ovulation disorders, Polycystic Ovary Syndrome (PCOS), gestational diabetes, hypertension, preterm births, and other complications. Improving metabolic health before conception is one of the most important steps to reduce risks for both mother and fetus.

Medications may improve fertility

Along with weight loss, GLP-1 family medications improve insulin sensitivity and reduce chronic inflammation. Studies have shown that women with PCOS experienced improvements in ovulatory cycles, menstrual frequency, and the success rates of fertility treatments. However, researchers note that it is not yet possible to determine to what extent this effect is due to the medication itself versus weight loss.

Can treatment continue during pregnancy?

As of today, the official recommendation is clear: do not use GLP-1 family medications during pregnancy. The reason is not evidence of proven harm, but a lack of large-scale studies confirming their safety throughout the entire pregnancy period.

Exposure in early pregnancy

An important conclusion from the review is that data from 34 studies, involving thousands of women, showed no increase in birth defects compared to the general population. If a woman discovers she is pregnant while on treatment, the recommendation is to stop immediately and consult a doctor; however, the exposure itself is not currently a reason for terminating the pregnancy.

What about breastfeeding?

Data remains limited. In a small study of eight breastfeeding women treated with semaglutide, the medication was not found in breast milk, and no side effects were reported in infants. Nevertheless, researchers emphasize that the sample size is too small to recommend routine use during breastfeeding.

Open questions

Researchers stress that further studies are required. It remains unknown what the ideal time frame is to stop treatment before trying to conceive, or what the long-term effects are on children exposed to these drugs in the womb. According to Dr. Osnat Raziel, director of the Multidisciplinary Center for Obesity Treatment at Assuta Medical, the main message is that treating obesity before pregnancy can significantly improve health outcomes, but medications must be stopped when planning a pregnancy or immediately upon its discovery, under medical supervision.