Scientists cautiously suggest GLP-1s are safe to use around pregnancy
Researchers from the School of Medicine at the University of St Andrews have cautiously suggested that the use of popular weight‑loss drugs around the time of pregnancy does not appear to increase the overall risk of major birth defects.
The findings come from the largest systematic review to date of pregnancies exposed to GLP‑1 receptor agonists, including drugs such as Ozempic, Wegovy and Mounjaro. Published in the American Journal of Obstetrics and Gynaecology, the review examined data from more than 49,000 pregnancies exposed to these weight-loss drugs.
GLP‑1 drugs are increasingly used by women to treat diabetes and obesity, and by women hoping to conceive in efforts to meet BMI requirements for fertility treatment. The UK Medicines regulator MHRA advises not to use GLP-1s during pregnancy due to safety concerns raised in preclinical studies, but inadvertent exposure around conception is becoming more common.
The analysis found no statistically significant link between periconceptional exposure to GLP‑1 drugs and major adverse foetal, pregnancy, obstetric or labour outcomes. A small association with renal malformations was identified, though researchers stressed this finding should be interpreted with caution, as it is likely influenced by underlying maternal conditions such as obesity or diabetes, which are themselves linked to kidney abnormalities.
Researchers say the results offer cautious reassurance for women who become pregnant unexpectedly while taking these medications, but do not support their routine use during pregnancy. They also highlight the need for further large‑scale studies with long‑term follow‑up.
Senior author, Dr Javier Tello, member of the Cellular Medicine Division in the School of Medicine said:
“This study tackles an important clinical question amid the surge in weight-loss drug use: their effects on pregnancy. Our findings offer cautious reassurance for women who become pregnant unexpectedly while on these medications but do not endorse routine use during pregnancy.”
The study has sparked interest from the media and Dr Tello was interviewed by STV on 1 May 2026, and the story was published on the STV website ahead of the broadcast of the interview.