A late period. A weekly pen in the fridge. Two lines on a test.
If you’ve lived that moment, or you’re quietly worried about it, this one’s for you. Millions of women of childbearing age now use GLP-1 medications, and plenty of pregnancies happen without much planning. On October 23, Reuters reported on a new analysis that touches GLP-1 and pregnancy, and the headline sounds comforting. The details are more mixed. So let’s go through them slowly.
What did the researchers actually look at?
The work comes from nference, a data analytics company in Cambridge, Massachusetts. The team found 572 pregnancies in women who’d had a prescription for semaglutide within 90 days before their last menstrual period. Of those women, 246 kept using the drug after they became pregnant. For comparison, the researchers also gathered 101,159 similar pregnancies with no GLP-1 use at all.
Then they compared outcomes. Women who continued and women who stopped looked alike on preeclampsia (a blood pressure problem linked to pregnancy), gestational diabetes (diabetes that first shows up during pregnancy), preterm birth, stillbirth and newborn death. Similar shares of pregnancies reached the second trimester, the third and delivery. Apgar scores, the quick health check babies get right after birth, matched as well. The women who continued also gained weight at a pace that fits a normal pregnancy.
Reassuring? A little. And “a little” is the honest size of it.
Why can’t we call this proof?
Start with peer review. That’s the step where independent experts go through a study’s methods before it’s published, and this analysis hasn’t been through it. The authors themselves say larger studies are needed to establish safety, which is a polite way of saying they don’t consider the question closed.
Next, look at who was still taking the drug later. Most women who continued stopped after the first trimester. Only 54 were prescribed it in the second trimester and 45 in the third. Those numbers are too small to tell us much about longer exposure.
It’s also an observational study. Researchers watch what happens to people who made their own choices, so they can spot patterns but can’t prove what caused them. And the Reuters summary doesn’t mention major birth defects at all, even though that’s one of the main worries when a drug is taken early in pregnancy.
So think of it as an early signal. Useful. Not a verdict.
What have bigger studies said about GLP-1 and pregnancy?
This analysis follows earlier work, and the earlier work is worth knowing.
In June, Harvard researchers reported on 3,572 pregnancies in women who used GLP-1 drugs before conception. Semaglutide was the most commonly dispensed drug in that group. The chance of a pregnancy ending without a live birth was 29.7% when women continued into the first trimester and 27.1% when they stopped. That gap wasn’t statistically significant. Even so, the estimates for birth weight and birth defects were imprecise, and women who continued were somewhat more likely to have type 2 diabetes, which can affect pregnancy by itself.
A separate US study in Obstetrics & Gynecology found something that surprised me less than it might surprise you. Women who had used the drug before pregnancy had higher risks of excessive weight gain, gestational diabetes, a larger-than-expected baby and cesarean delivery than women who’d never used it. Those risks looked about the same whether the women stopped beforehand or continued. The researchers suggested that rapid weight regain after stopping may explain part of the pattern, rather than the drug reaching the baby.
Pooled evidence tells a similar story. A 2026 review combining several studies found no statistically significant increase in major birth defects after first-trimester exposure. The range of possible results was wide, though, so a small increase can’t be ruled out. And an August analysis of 249 reports in the FDA’s adverse event database described the human evidence as extremely limited and said intentional use in pregnancy remains off the table.
Why the caution at all? Animal studies. In animal models, drugs in this class were linked to lower fetal weight, delayed bone formation, skeletal and organ abnormalities, and more embryo loss. Animals aren’t people, and those findings don’t automatically carry over. They do explain the warnings, though.
What does the label say, and why?
The U.S. Food and Drug Administration label for Wegovy says the drug may cause fetal harm. For people using it for weight reduction, it says to stop when pregnancy is recognized. It also says to stop at least two months before a planned pregnancy.
Two months sounds oddly long, doesn’t it? It comes down to how slowly the drug leaves the body. It has a long half-life, meaning it takes several weeks to clear, so stopping the week you start trying doesn’t leave you drug-free.
One researcher on the Harvard study was clear that her findings alone can’t change the guidance. Her advice was to follow the label and your clinician’s advice. In plain terms, GLP-1 medications still aren’t recommended during pregnancy, and one reassuring study doesn’t change that.
How does anyone end up pregnant on these drugs?
Quite easily, as it turns out.
Ozempic and Wegovy contain the same drug. It copies a gut hormone that slows stomach emptying, raises insulin after meals and tells your brain you’re full. Weight loss and better insulin response from GLP-1 medications can also restore regular ovulation in some women, particularly those whose obesity was disrupting their hormones. Someone who rarely ovulated before may now ovulate every month.
Add the fact that about 40% of pregnancies in the US are unplanned, and surprises stop being surprising.
Birth control can complicate things too. Reuters has reported that tirzepatide, sold as Mounjaro and Zepbound, can reduce how well the body absorbs oral contraceptives. And nausea, a very common effect of these drugs, makes it easy to blame the injection for what might be early pregnancy.
Found out you’re pregnant? Here’s a sensible order of events
First, take the result seriously and call your prescriber or your obstetric provider soon. Not tomorrow-when it’s convenient. This week.
Your doctor will probably confirm the pregnancy with a urine or blood test and estimate how far along you are with an early ultrasound. They’ll also ask when you took your last dose. That timing matters, because it tells them roughly how much exposure happened and for how long.
If you take the drug for type 2 diabetes, don’t stop it on your own. Poorly controlled blood sugar carries real risks for you and the baby. Doctors may move patients to options with longer pregnancy track records, such as insulin, and that decision belongs in a conversation, not a guess.
Expect closer follow-up than usual. Because weight can rebound after stopping, your provider may watch your weight gain and screen for gestational diabetes. A detailed anatomy ultrasound, usually done around the middle of pregnancy, looks closely at the baby’s development.
Is any of this scary? It can feel that way. But the studies so far don’t point to a clear, large harm, and a good follow-up plan is the best response to uncertainty.
Planning a baby? Start earlier than you’d think
Talk with your prescriber before you start trying. Planning around GLP-1 and pregnancy means stopping the drug at least two months ahead, as the label advises, and using reliable contraception until then. If you take tirzepatide or any oral birth control, ask whether you need a non-oral method or a backup.
Weight tends to return after stopping, so ask for a nutrition and activity plan before conception rather than after. Ask about prenatal vitamins with folic acid too.
Prefer tablets to injections? A daily GLP-1 pill isn’t a loophole. Wegovy’s pregnancy advice appears in one combined label that covers both the tablet and the injection.
When it’s more than ordinary stomach trouble
Common side effects of GLP-1 medications include nausea, vomiting, constipation and diarrhea. If you’d like the fuller list, including reactions beyond the stomach, here’s more on side effects. In pregnancy, heavy vomiting can lead to dehydration quickly.
Get urgent care if you can’t stop vomiting, can’t keep fluids down, or have severe belly pain that spreads to your back. That pain can signal pancreatitis, an inflamed pancreas, which is a listed warning on the label. Also seek care for vaginal bleeding, sharp pain on one side, fainting, or very high or low blood sugar readings if you have diabetes.
What we still don’t know
Plenty. The coverage I reviewed focuses on pregnancy and delivery, not on how children do years later. Exposure in the second and third trimesters is barely studied. And no one yet knows whether rapid weight changes around conception matter more than the drug itself.
Larger studies, run in a way that follows women over time, are what the researchers are asking for. Until they arrive, the practical advice stays the same: plan ahead, follow the label and talk to your doctor early.
FAQs
Will stopping the drug right away protect my baby?
The label advises stopping once pregnancy is recognized, but the drug stays in your body for weeks. Earlier exposure may already have happened, which is why your doctor will want to date the pregnancy and monitor it closely.
Does the trimester of exposure matter?
It may, but this analysis can’t say. Most women stopped after the first trimester, and only 54 continued into the second and 45 into the third.
Does the same advice apply to the pill form of semaglutide?
The current Wegovy label covers the tablet and the injection in one document, with the same pregnancy guidance. Ask your prescriber about your exact product.
Can I breastfeed while taking a GLP-1 drug?
The current label says breastfeeding isn’t recommended with Wegovy tablets. Ask your doctor about other forms, and settle a feeding plan before delivery.
Do these drugs make birth control fail?
Tirzepatide can reduce oral contraceptive absorption, according to Reuters. The evidence for other drugs is less clear, so ask your doctor whether your GLP-1 medications and birth control need a backup.
Does the new analysis mean it’s safe to keep taking the drug?
No. The study is preliminary, and its authors want larger studies. The label still says to stop. Anyone weighing GLP-1 and pregnancy choices should decide with their doctor.
