You probably know someone taking Ozempic or Wegovy. Many of those users are women of reproductive age, and not all of them are planning a pregnancy right now. That is what makes a new signal from the lab worth reading.
In pregnant sheep, a single dose of semaglutide significantly cut the mother's cardiac output within two hours. Blood flow to the uterus dropped, and oxygen levels in the developing fetus fell with it.
Semaglutide is the active ingredient in Novo Nordisk's Ozempic and Wegovy. The work was published as a conference abstract in Heart, Lung and Circulation by researchers at Adelaide University.
The team used MRI to track maternal heart function and uterine blood flow before and after the drug was given. They also took fetal blood samples and monitored the fetal heart rate.
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What this animal study can and cannot say
This was a short-term experiment in sheep, not a trial in pregnant women. The researchers have not shown that the shifts in blood flow translate into fetal growth problems in humans.
They have also not tested continued weekly dosing, which is how women actually take these drugs. What the work adds is a biological mechanism that could explain why pregnancy guidance has stayed cautious.
Dr Mitchell Lock, who led the work, has said that any reduction in fetal oxygen raises questions about what might happen if exposure to the drug continues through pregnancy.
Current guidance already advises stopping before conception
The American College of Obstetricians and Gynecologists issued a new practice advisory on October 28, 2026. ACOG recommends considering discontinuation 1 to 2 months before conception, and advises against GLP-1 use during pregnancy.
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Part of the reason is the long half-life of these drugs. Semaglutide stays in the body for weeks after the last injection, so simply stopping when pregnancy is confirmed may not be early enough.
Awareness is still low. ACOG estimates that as many as 1 in 300 women are exposed to GLP-1 drugs before pregnancy, and many of those pregnancies are unplanned.
What this means if you are on Ozempic or Wegovy
If you take a GLP-1 drug and could become pregnant, talk to your doctor about timing and contraception. Past accidental exposure does not automatically mean harm.
Large reviews of women who conceived while on a GLP-1 drug have so far not shown a clear rise in miscarriage or birth defects. Researchers caution that no detected signal is not the same as proven safety.
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Our earlier explainer on Ozempic, Wegovy and pregnancy covers the human data in more detail.
The Adelaide team plans to study whether the short-term changes in blood flow and oxygen produce measurable effects on fetal growth over longer exposure.
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This article is made and published by Mie Hermansen, who may have used AI in the preparation.