New research suggests that stopping GLP‑1 medications like ozempic before pregnancy may be associated with higher rates of pregnancy complications and greater gestational weight gain, though experts caution the findings do not prove causation.
Study details
A JAMA study reviewed several hundred singleton births within the Mass General Brigham system from 2016–2025. Researchers identified roughly 450 pregnancies in which the parent had used a GLP‑1 medication at some point between three years before conception and the first 90 days after conception. About half had their last GLP‑1 prescription within six months of conceiving, roughly one‑third had stopped earlier, and about 17% had prescriptions after conception. The average prepregnancy BMI in the GLP‑1 group was about 36 (in the obesity range). Outcomes were compared with a group who had never used GLP‑1s but had similar prepregnancy BMIs and BMI category distributions.
Findings
Compared with the matched nonuser group, people who had used then stopped GLP‑1s experienced higher rates of:
– Preterm birth
– Gestational diabetes
– Hypertensive disorders of pregnancy, including high blood pressure and preeclampsia
They also gained more weight during pregnancy—about 30 pounds (13.7 kg) on average versus about 23 pounds (10.5 kg) in the comparison group—and a larger share met criteria for excessive gestational weight gain.
Interpretation and limitations
Experts emphasize important limitations. Many people prescribed GLP‑1s have obesity, insulin resistance, or other metabolic disease that itself increases pregnancy risk; this confounding by indication makes it difficult to attribute outcomes directly to GLP‑1 exposure or discontinuation. Stopping GLP‑1s can cause rebound appetite and worse blood‑sugar control, which may contribute to weight regain and metabolic instability before or during pregnancy. Current guidance recommends stopping GLP‑1s before conception—typically at least two months prior—because these drugs remain in the body for weeks.
Safety data and unknowns
Animal studies at high doses have linked GLP‑1 exposure to fetal growth restriction, structural abnormalities, and pregnancy loss, often alongside maternal weight loss, which is why labels advise against use in pregnancy. Human data are limited and mixed; so far no clear pattern of major birth defects has emerged, but there is insufficient evidence about more subtle outcomes or long‑term effects on children. Experts say the main risk now is uncertainty and the need for pregnancy‑specific research.
Clinical perspective
Rather than viewing this as a simple tradeoff between GLP‑1s and obesity, clinicians note that obesity and metabolic disease remain primary drivers of pregnancy complications. Prepregnancy obesity and excess gestational weight gain are consistently linked to gestational diabetes, hypertensive disorders, cesarean birth, and long‑term metabolic risks for offspring. GLP‑1 use followed by abrupt discontinuation may add instability on top of those underlying risks. Given limited pregnancy safety data, most experts do not feel the potential benefits of continuing GLP‑1s during pregnancy currently outweigh the unknowns; established alternatives like insulin have much longer safety records in pregnancy.
Practical guidance
GLP‑1 drugs are not recommended during pregnancy. For those planning pregnancy, clinicians advise:
– Discussing timing of stopping GLP‑1s and creating a transition plan with a healthcare provider
– Focusing on balanced nutrition that supports appropriate pregnancy weight gain for your BMI (regular meals and snacks, protein, high‑fiber carbohydrates, fruits and vegetables, healthy fats)
– Incorporating gentle, regular activity as appropriate (short walks after meals, brief resistance exercises)
– Managing stress, sleep, and nausea, which affect appetite and eating behavior
– Seeking professional support: structured behavioral counseling in pregnancy can reduce excess gestational weight gain and lower risks of gestational diabetes, emergency cesarean, and very large infants
– Monitoring blood sugar and metabolic health closely if stopping GLP‑1 therapy
Bottom line
Stopping GLP‑1 medications before pregnancy was associated in this study with higher rates of certain complications and greater gestational weight gain, but underlying obesity and metabolic disease probably play a major role. GLP‑1s are not recommended during pregnancy; those planning pregnancy should work with clinicians on cessation timing, metabolic monitoring, and nutrition and activity plans to minimize risks. More pregnancy‑specific research is needed to clarify benefits and harms.
