Semaglutide pregnancy case series

A 2026 case series followed 16 singleton pregnancies with inadvertent first-trimester exposure to subcutaneous semaglutide. No major congenital anomalies were identified, but this small, retrospective series cannot establish that semaglutide is safe in pregnancy. Three patients developed preeclampsia, and one delivery occurred at 35 weeks because of severe preeclampsia and uncontrolled diabetes^[1]. Current US Wegovy labeling says pregnancy data are insufficient to establish drug-associated risk and advises discontinuation when pregnancy is recognized for patients using it for weight reduction^[2].

What the researchers reviewed

The authors reviewed records from a tertiary perinatal center in Canada. Eligible patients had exposure to a GLP-1 receptor agonist from two months before conception through the end of pregnancy. Among 1,016 new clinic patients seen from August 2023 through October 2024, 16 met the exposure criteria. Every exposure in the final series was to subcutaneous semaglutide, so the findings cannot be transferred to other medicines in the class^[1].

Fifteen patients had used semaglutide for type 2 diabetes and one for obesity. Their mean age was 34.6 years, and mean pre-pregnancy BMI was 35.0 kg/m². All conceptions were spontaneous and unplanned. The latest documented exposure was at 8 weeks and 2 days of pregnancy. The study used existing clinical records and descriptive statistics, with no unexposed comparison group^[1]. Background on the medicine and its approved uses appears on our semaglutide overview.

What happened in the 16 pregnancies

The authors identified no major congenital anomalies and no diagnosed fetal growth restriction. One fetus had a thick nuchal fold, but aneuploidy testing and chromosomal microarray were normal. Median gestational age at delivery was 37 weeks and 6 days. Four newborns were admitted to neonatal intensive care, and 10 births were by cesarean delivery^[1]. These are observed outcomes in a selected clinic series, not estimated rates for all exposed pregnancies.

Three patients developed gestational hypertension and three developed preeclampsia, giving a preeclampsia proportion of 18.8% in this small group. One patient delivered at 35 weeks after induction for worsening preeclampsia and uncontrolled diabetes. The authors noted that obesity and type 2 diabetes were common in the series and could have contributed to those outcomes. The design cannot separate any effect of semaglutide exposure from those underlying conditions^[1].

Diabetes care changed after discontinuation

After semaglutide was stopped, 10 of the 16 patients were managed with both insulin and metformin. The basal insulin requirement before delivery ranged from 0 to 260 units. That wide range reflects differing clinical needs within a group in which almost everyone had pre-existing type 2 diabetes. It should not be read as a dosing guide or as proof that stopping semaglutide caused a particular insulin requirement^[1]. Medication changes during pregnancy belong with an obstetric and diabetes care team.

No patient lost weight during pregnancy. Gestational weight gain was classified as adequate in eight patients and inadequate in two. It was excessive in six under Institute of Medicine criteria. The authors described the 37.5% excessive-gain proportion as lower than expected for a population with substantial obesity, but comparisons with other cohorts cannot establish cause. Patient-reported pre-pregnancy weight was also used in the calculation^[1]. Our semaglutide safety guide explains why observational signals need careful interpretation.

Why no anomalies does not prove safety

A series of 16 births is too small to detect a modest increase in an uncommon outcome. It also excluded early pregnancies that never reached the tertiary clinic. The authors specifically noted that miscarriages before 12 weeks could have been missed because prenatal booking often occurs later. Without an unexposed group matched for diabetes, BMI, age, and other risks, the study cannot estimate whether exposure changed the chance of an anomaly, preeclampsia, preterm delivery, or neonatal admission^[1].

The current US Wegovy label reaches the same practical evidence boundary. It says available pharmacovigilance and clinical-trial data in pregnant patients are insufficient to establish drug-associated risk. That uncertainty covers major birth defects and miscarriage as well as adverse maternal or fetal outcomes. The label also describes adverse findings in animal reproduction studies and maintains a pregnancy exposure registry^[2]. Regulatory details and label links are collected on our semaglutide regulation page.

What to do after an inadvertent exposure

This case series is reassuring only in a limited sense: no major congenital anomaly was found among the 16 recorded births. It does not justify continuing, starting, or restarting semaglutide during pregnancy. US labeling states that weight loss offers no benefit during pregnancy and may cause fetal harm, and it directs clinicians to discontinue Wegovy in pregnant patients using it for weight reduction^[2]. Someone who learns they are pregnant after exposure should contact the clinician managing the prescription and their prenatal care rather than making decisions from a case-series headline.

What we do not yet know

The paper cannot tell us whether timing, duration, or dose changes risk. It cannot quantify miscarriage because early losses may not have entered the clinic records. Nor can it isolate semaglutide from pre-existing diabetes, obesity, hypertension, or the treatment changes made after pregnancy was recognized. Larger prospective studies and pregnancy-registry data are needed to estimate uncommon outcomes and compare like patients^[1][2].

The honest summary is simple. Sixteen observed pregnancies add useful detail to a sparse human evidence base, but they do not overturn the label or establish safety. The lack of major anomalies in this series is one data point, while the high-risk clinical backgrounds and incomplete capture of early losses keep the result from answering the larger risk question. Our semaglutide evidence page will track stronger evidence as it appears.