Women who took GLP-1 weight-loss and diabetes drugs around the time they conceived were no more, and no less, likely to develop high blood pressure during pregnancy. That is the finding of the first pooled analysis of the question, published July 31 in Endocrine ↗. The honest catch is that the pooled answer rests on only three studies, all from the United States, and they did not agree with each other.
The condition at stake is what obstetricians call hypertensive disorders of pregnancy. That covers gestational hypertension, high blood pressure that shows up in the second half of pregnancy. It also covers preeclampsia, a more dangerous version that adds organ strain. Preeclampsia is one of the leading causes of harm to mothers and babies worldwide. Anything that might raise or lower that risk in early pregnancy is worth knowing about.
The drugs in question are the GLP-1 receptor agonists, the injected medicines that mimic a gut hormone to lower blood sugar and appetite. The analysis pooled exposure to semaglutide ↗, sold as Ozempic and Wegovy, tirzepatide ↗, sold as Mounjaro and Zepbound, liraglutide ↗, and four older agents (dulaglutide, exenatide, lixisenatide, and albiglutide). These drugs are not approved for use in pregnancy and their labels tell patients to stop before conceiving. The problem is that real life does not always cooperate. The drugs improve fertility by lowering weight and insulin resistance, unplanned pregnancies happen, and some women are already several weeks along before they know to stop. That makes the early-exposure window a genuine safety unknown rather than a hypothetical.
A team led by Marco La Verde at the University of Campania Luigi Vanvitelli in Naples searched the medical literature through December 2025 for studies that measured this exact thing. Co-authors joined from Udine, Florence, and Charles University in Prague. Of 75 records, three retrospective cohort studies fit. Together they covered 10,880 pregnancies, 4,942 exposed to a GLP-1 drug around conception or in the first trimester and 5,938 not exposed. All three were run in the United States between 2014 and 2025.
Two of the three studies pointed to lower blood-pressure risk in the exposed group; the third pointed the other way. Pooling them gave an odds ratio of 0.91, with a confidence interval running from 0.57 to 1.47. In plain terms, that is about 9 percent lower odds of a hypertensive disorder, but the range stretches from a 43 percent reduction to a 47 percent increase. It comfortably includes no effect at all, which is why the authors call the result not significant.
A null result here is reassuring on its face, but it is absence of a signal, not proof of safety. Three observational cohorts is a thin base, and observational is the operative word. Women prescribed these drugs have diabetes or obesity, both of which raise the risk of pregnancy hypertension on their own. Comparing exposed to unexposed women who share those conditions is the right design, and these studies did that, but retrospective records cannot rule out that the two groups still differed in ways nobody measured. The authors graded the risk of bias with a standard tool and reached the conclusion that fits the data: no significant association, and not enough evidence to call it either way. What the field needs is a large prospective study built to answer the question, not three back-looking cohorts pooled after the fact.
The value of the piece is what it does not find. There is no early alarm bell in the existing data, which matters for the growing number of women who conceive while on these drugs and worry about what the exposure did. It is the same shape as the absence of a melanoma signal ↗ that a much larger matched analysis reported earlier this week. Both are GLP-1 safety questions that land on reassurance from observational data. Both carry the same caveat, that observational data can only rule out a large effect, not a small one. On peptidemodel, the pooled drugs sit against the GLP-1 receptor ↗, and tirzepatide also against the GIP receptor ↗ it hits at the same time. The pregnancy question is one of the last big safety gaps for a drug class that is now in tens of millions of bodies, some of them pregnant before anyone intended.