Quick answer: “Ozempic babies” refers to unplanned pregnancies in people taking GLP-1 drugs. Two things drive it: weight loss can restore ovulation in people who were not ovulating regularly, and tirzepatide (Mounjaro, Zepbound) can lower the levels of birth control pill hormones, so the labels advise a non-oral or backup method for 4 weeks after starting and after each dose increase.[1][2][5] The labels say to stop these drugs when pregnancy is recognized, and to stop semaglutide at least 2 months before a planned pregnancy.[3][4]
This guide explains why surprise pregnancies happen, what the labels say about contraception and pregnancy, and what the outcome data show so far. For background, see our GLP-1 basics hub, and the tirzepatide and semaglutide profiles.
Why some people get pregnant on GLP-1 drugs
Weight loss can restore fertility
Obesity and conditions linked to it, such as polycystic ovary syndrome (PCOS), can cause irregular or absent ovulation. A 2025 review in the American Journal of Obstetrics & Gynecology noted that many women previously diagnosed with irregular periods and unable to conceive have had unplanned pregnancies after losing weight on these drugs.[5] If you were told it would be hard to get pregnant, that may change as weight comes off.
Tirzepatide can reduce birth control pill levels
GLP-1 drugs slow stomach emptying, which can change how pills are absorbed. For tirzepatide, this was measured. After a single 5 mg dose, peak blood levels of a combined pill’s hormones fell by 59% (ethinyl estradiol), 66% (norgestimate) and 55% (norelgestromin), and overall exposure fell by about 20% to 23%.[1]
The Mounjaro and Zepbound labels say this delay is largest after the first dose and lessens over time, and advise people on oral hormonal contraceptives to:[1][2]
- switch to a non-oral method (such as an IUD, implant, injection, patch or ring), or
- add a barrier method (such as condoms) for 4 weeks after starting and 4 weeks after each dose increase.
Hormonal contraceptives that are not taken by mouth should not be affected.[1]
Semaglutide and the pill
The semaglutide labels do not carry this warning. In an interaction study at the 1 mg steady-state dose, semaglutide had no clinically relevant effect on an ethinylestradiol/levonorgestrel pill.[4] However, vomiting or severe diarrhea, both common GLP-1 side effects, can make any pill less reliable. See GLP-1 nausea for how often that happens.
What the labels say about pregnancy
| Drug | Before a planned pregnancy | If pregnancy happens | Registry |
|---|---|---|---|
| Ozempic | Stop at least 2 months before | Label notes limited data; discuss with clinician | None listed |
| Wegovy (weight loss or heart risk) | Stop at least 2 months before | Stop when pregnancy is recognized | Wegovy pregnancy registry |
| Mounjaro | Use reliable contraception (see above) | Label notes limited data; discuss with clinician | None listed |
| Zepbound | Use reliable contraception (see above) | Stop when pregnancy is recognized | Lilly pregnancy registry |
Sources: Ozempic, Wegovy, Mounjaro and Zepbound labels.[1][2][3][4]
The 2-month washout for semaglutide reflects its long half-life of about a week. The Zepbound label also notes that weight loss is not recommended during pregnancy and that animal studies showed harm, while human data are too limited to judge the risk of birth defects or miscarriage.[1] For how long these drugs linger, see our GLP-1 dose conversion chart.
What the data show about babies exposed early
No randomized trials have tested these drugs in pregnancy, so evidence comes from observational studies:
- Birth defects, large international study (2024): Among infants of mothers with type 2 diabetes in the Nordic countries, the US and Israel, early-pregnancy exposure to GLP-1 drugs was not linked to more major birth defects than insulin (adjusted relative risk 0.95, 95% CI 0.72 to 1.26).[6]
- Teratology services cohort (2024): In 168 pregnancies exposed in the first trimester, major birth defects occurred in 2.6%, similar to comparison groups with diabetes (2.3%) or overweight/obesity (3.9%). There was no increase in pregnancy loss.[7]
- Continuing into the first trimester (2026): In 3,572 US pregnancies, continuing GLP-1 drugs into early pregnancy was not definitively linked to more non-live births, birth defects or growth problems, but some estimates were imprecise and could not rule out meaningful risk.[8]
- After stopping (2025): In a US health system, women who stopped GLP-1 drugs before or early in pregnancy gained more weight during pregnancy (13.7 kg vs 10.5 kg) and had higher rates of preterm birth, gestational diabetes and high blood pressure disorders than matched women who had not used them.[9]
If you are pregnant or planning a pregnancy
- Planning: talk to your clinician before stopping, and stop semaglutide at least 2 months ahead as the labels advise.[3][4] Ask about a plan to manage weight and blood sugar once off the drug, given the 2025 findings on weight gain.[9]
- Unexpected pregnancy: stop the drug, contact your clinician, and ask about the manufacturer pregnancy registry. Do not panic; the available data do not show a large increase in birth defects.[6][7]
- Breastfeeding: Wegovy’s label advises against breastfeeding while taking Wegovy tablets; ask your clinician about the injection and other drugs.[3]
Questions to ask your clinician
- Which contraception works best with my GLP-1 drug and my health history?
- If I am on the pill and take Mounjaro or Zepbound, when do I need backup protection?
- How far ahead should I stop before trying to conceive?
- How will we manage my weight and blood sugar during pregnancy if I stop?
- Should I take folic acid now in case of an unplanned pregnancy?
Related guides
Planning a procedure such as egg retrieval or a C-section under anesthesia? See stopping GLP-1s before surgery. For other common side effects, see GLP-1 fatigue.
This article is general information. Your clinician can help you choose contraception and plan a pregnancy around GLP-1 treatment.
