Ozempic Babies: Why Unexpected Pregnancies Happen on GLP-1s

“Ozempic babies” is the social-media nickname for unexpected pregnancies in people taking GLP-1 medications such as Ozempic, Wegovy, and Rybelsus (semaglutide), Mounjaro and Zepbound (tirzepatide), Trulicity (dulaglutide), and Byetta (exenatide) [1, 2, 3]. The effect is not specific to Ozempic, and none of these drugs is approved for fertility — their approvals cover diabetes, obesity, and sleep apnea, so any fertility boost is a side effect [1, 2].

The main reason these pregnancies happen is weight loss. Losing weight can restore ovulation, sometimes without a person noticing, and semaglutide has not been shown to reduce blood levels of oral contraceptives [4, 5]. Tirzepatide is different: it cut oral contraceptive hormone levels by up to 66% in one study, and its labels carry a specific backup-contraception warning [2, 4, 5]. The Wegovy label says to stop at least 2 months before a planned pregnancy, and human pregnancy data so far are low-certainty — reassuring for accidental exposure, but not proof of safety [6, 8].

What are ‘Ozempic babies’?

The term spread through the hashtag #Ozempicbabies on social media as people reported conceiving while on these drugs [1, 3]. Cleveland Clinic Ob/Gyn Deidre McIntosh described it as an “Ozempic baby boom,” with patients who had tried for years conceiving while taking these medications ^[1].

Clinicians report similar effects with tirzepatide (Mounjaro, Zepbound), dulaglutide (Trulicity), exenatide (Byetta), oral semaglutide (Rybelsus), and Wegovy [1, 2, 3]. A trial called RESTORE, run by the University of Colorado Anschutz, is testing whether semaglutide or metformin can restore ovulation in people with PCOS and obesity, with a preliminary subset analysis published in Fertility and Sterility in 2026 — but semaglutide is not approved as a fertility treatment ^[15].

Does Ozempic make you more fertile?

It can, indirectly, mainly through weight loss. Obesity disrupts ovulation, and McIntosh notes that each BMI point above 29 lowers female fertility by about 5% ^[1]. Reproductive endocrinologist Sharrón Manuel of HRC Fertility attributes the effect to weight loss and metabolic improvement restoring ovulation, reversing problems such as disruption of the hypothalamic-pituitary-ovarian axis, insulin resistance, altered sex steroid metabolism, and reduced egg and endometrial quality ^[2].

Preclinical data also suggest possible direct effects — on luteinizing hormone secretion, ovarian morphology, and endometrial receptivity — independent of weight loss, but this has not been proven in humans [2, 15].

Why do unexpected pregnancies happen on these drugs?

As weight falls, ovulation can resume without warning. People who assumed they could not conceive may stop using contraception, and cycles can normalize quietly as weight decreases ^[2].

People with PCOS may see the biggest effect, because PCOS is closely tied to insulin resistance and weight gain [2, 4]. PCOS is the most common endocrine condition in women, potentially affecting up to 15% of the female population, according to Nanette Santoro of the University of Colorado ^[4]. The 2023 international PCOS guideline lists GLP-1 anti-obesity medication as an option for higher-weight adults with PCOS ^[3].

How common are these pregnancies?

No one knows. The effect has not been quantified, and there is no figure for the percentage of users who conceive in a given timeframe ^[1]. Reports so far are anecdotal; GLP-1s have never been studied as fertility treatments, and women planning pregnancy were excluded from the semaglutide and tirzepatide trials ^[3].

Zaher Merhi, a reproductive endocrinologist, says there are zero studies of GLP-1s and fertility or menstruation in women without PCOS ^[4]. Christina Boots of Northwestern says there is not yet good evidence that GLP-1s improve ovulation or pregnancy odds in PCOS, though they may help make periods more regular ^[4]. A 2025 review of 12 small weight-loss trials found modest gains in natural conception and none in IVF outcomes ^[4].

Does Ozempic affect birth control pills?

Semaglutide has not been shown to weaken the pill. A 2024 literature review led by pharmacist Jessica Skelley of Samford University found semaglutide did not reduce oral contraceptive blood levels or significantly delay absorption ^[4]. Semaglutide has not been shown to reduce the effectiveness of either the combined pill or the progestin-only pill ^[5].

The Wegovy label states only that the drug delays gastric emptying and may impact absorption of oral medications generally; it carries no specific oral contraceptive warning in its highlights [6, 3]. Even so, McIntosh recommends backup contraception during dose-increase weeks because GLP-1s slow absorption ^[1].

Other GLP-1s reduced oral contraceptive plasma levels by up to 45% and delayed absorption by up to 3.5 hours — not enough to cause failure, per the same review ^[4]. Non-oral methods such as the IUD, implant, patch, ring, and shot are not affected [1, 3, 5].

Why is tirzepatide different for the pill?

Tirzepatide (Mounjaro, Zepbound) reduced oral contraceptive plasma hormone levels by up to 66% and delayed the peak by up to 4.5 hours, an effect seen even at the 5 mg dose ^[4]. Clue reports tirzepatide cuts oral contraceptive absorption by around 20% ^[5].

The reason is that tirzepatide acts on the GIP receptor as well as the GLP-1 receptor, producing a greater delay in gastric emptying ^[4]. The Mounjaro and Zepbound labels advise switching to a non-oral contraceptive or adding a barrier method for 4 weeks after starting the drug and for 4 weeks after each dose increase [2, 4, 5].

Can vomiting make the pill fail?

Separately from drug interactions, nausea and vomiting are common GLP-1 side effects and can stop a pill from being fully absorbed ^[5]. Nausea, diarrhea, and vomiting are among Wegovy’s most common adverse reactions ^[6].

Per the period-tracking app Clue: vomiting within 3 hours of a combined pill means the dose may not count, and a backup method is advised until 7 vomit-free days have passed; for most progestin-only pills, backup is advised until 2 days after recovery ^[5]. Specific pill-timing questions are best directed to a prescriber.

How long before pregnancy should semaglutide be stopped?

The Wegovy label says the drug may cause fetal harm and should be discontinued at least 2 months before a planned pregnancy because of semaglutide’s long half-life — advice that applies to Wegovy used for cardiovascular risk reduction, weight reduction, or MASH ^[6]. For tirzepatide, the washout is at least 1 month ^[5].

A 2024 CMAJ paper likewise recommends stopping 1 or 2 months before trying to conceive depending on the product, and Manuel advises 1 to 3 months depending on the drug’s pharmacokinetics ^[2]. GoodRx notes GLP-1s can be part of pre-pregnancy weight management, then transitioned off before conception ^[3]. Timing a washout is a decision to make with a prescriber.

Why is there a pregnancy warning at all?

Animal studies in mice, rats, and rabbits have shown embryofetal mortality, structural abnormalities, growth disturbances, delayed ossification, and skeletal variants [7, 9]. Kate Maslin of the University of Plymouth notes some of these animal effects are partly linked to reduced maternal food intake at high doses ^[4].

Pregnant women were excluded from trials for ethical reasons, and the FDA says a risk to a developing pregnancy cannot be ruled out ^[3]. A Wegovy pregnancy registry is running until summer 2027, and a Zepbound registry is expected; the manufacturer’s line for Zepbound exposure is 1-800-545-5979 ^[3].

What do human pregnancy data show?

Two meta-analyses published in 2026 found no significant increase in major birth defects, with low-certainty evidence:

Study	Exposed pregnancies	Major malformation result	Other findings
Uysal et al, Scientific Reports 2026 [8]	42,282 vs 723,892 comparators	Any malformation OR 1.11 (95% CI 0.82-1.51)	First-trimester major malformations OR 1.39 (0.73-2.65); cardiac OR 0.92; preterm OR 1.17 (0.79-1.72); spontaneous abortion OR 0.95; stillbirth OR 2.17 (0.95-4.91), not significant but not excluded
Liu et al, Endocrine Connections July 2026 [9]	43,577 vs 243,022 unexposed	RR 1.02 (95% CI 0.96-1.08)	Preterm RR 1.09 (0.80-1.49); LGA RR 2.31 (0.56-9.44); SGA RR 0.71; stillbirth RR 1.16 (0.24-5.69)

Uysal’s team rated certainty low or very low and described the findings as cautious reassurance for inadvertent exposure, not evidence that the drugs are safe for routine use; tirzepatide appeared in only one study ^[8]. Liu’s team wrote that the findings should not be interpreted as proof of safety ^[9]. One urinary malformation signal — OR 1.24 (1.05-1.47) — came from two unadjusted studies, was driven by one cohort, and may reflect confounding by diabetes or obesity rather than a drug effect ^[8].

National cohort studies point the same way. Kolding et al (2025) studied 104,422 singleton pregnancies in the Central Denmark Region and identified 32 first-trimester semaglutide exposures (27 Ozempic, 5 Wegovy) ^[7]. Major malformations occurred in 3 of 32 (9.4%), versus 13.9% with insulin and 7.7% unexposed — no increased risk ^[7]. Preterm birth was 20.0% versus 23.1% with insulin and 4.8% unexposed, and LGA, neonatal hypoglycemia, and jaundice were higher than unexposed but similar to insulin; with only 32 exposed pregnancies, no adjustment was possible ^[7].

Hviid et al (Human Reproduction Open, March 2026) analyzed 756,636 Danish singleton pregnancies with 529 periconceptional liraglutide or semaglutide exposures ^[10]. After propensity matching, only preterm birth remained elevated, and only in diabetes users — semaglutide aOR 1.84 (1.24-2.71), liraglutide aOR 1.70 — while weight-management users showed no association (semaglutide aOR 0.71, 0.30-1.70); the authors suggest diabetes, not the drug, drives it ^[10]. In Taiwan, Chou et al found no increased risks versus insulin in 160 GLP-1-exposed mothers with type 2 diabetes (malformations RR 0.64, stillbirth 2.05, preterm 1.09, SGA 0.86) and concluded intentional use in planned pregnancy is not advised ^[11]. A 2025 systematic review of 1,128 exposed pregnancies found no consistent increased malformation risk, though one study linked discontinuation to fetal macrosomia and neonatal hypoglycemia ^[12]. An earlier prospective cohort of 168 first-trimester exposures (Dao et al, BMJ Open 2024) found no increased major birth defects or pregnancy loss, but the sample was small [1, 2].

Across these studies, comparison groups had diabetes or obesity with raised baseline risks, exposed numbers were small, and rare outcomes were not excluded [7, 8, 9].

What if you get a positive pregnancy test on a GLP-1?

Fertility specialists advise stopping the drug right away and telling the OB/GYN about the exposure, with a possible referral to maternal-fetal medicine [2, 3]. Cleveland Clinic notes the provider will likely recommend stopping and may suggest pregnancy-safe alternatives for diabetes, with the decision individualized ^[1]. The human data so far are reassuring but low-certainty [2, 3, 8].

Can you take semaglutide while breastfeeding?

The Wegovy label states breastfeeding is not recommended during treatment with Wegovy tablets ^[6]. Small studies have found injectable GLP-1s are not present in breastmilk and are not passed to nursing infants — not true of oral GLP-1s — and the general advice is to avoid these drugs while breastfeeding unless the benefits far outweigh the risks ^[3].

Do GLP-1s affect male fertility?

Early data suggest no harm and possible benefit. About half of infertility in couples involves a male factor, and BMI is associated with semen quality, according to Stanford reproductive urologist Michael Eisenberg ^[4]. A urology review by Kuchakulla et al (July 2026) covered 16 clinical studies and found GLP-1 receptors in the testes, with limited clinical data suggesting improved semen parameters and testosterone in obese hypogonadal men; larger studies are needed ^[13].

In a 2025 randomized trial by Gregorič et al, obese men with type 2 diabetes and hypogonadism took semaglutide 1 mg weekly for 24 weeks, and normal sperm morphology rose from 2% to 4% (P = .012) ^[13]. At ENDO 2026 (June 13, 2026, Chicago), Pratibha Natesh of Warwick Medical School presented a review of five RCTs in men 18-65 that found no harm to hormones, sexual function, or sperm quality [14, 15]. That review has not been peer-reviewed, the number of trials is small, and GLP-1s have not been evaluated as treatments for male infertility or hypogonadism [14, 15].

Natesh says the work supports a shift from testosterone replacement toward treating excess weight in obese men with low testosterone — notable because TRT suppresses sperm production, as urologist Philip Werthman explains [14, 15]. Eisenberg calls the studies very limited — a handful that do not support a negative effect — and notes a 2022 Novo-funded study where weight loss followed by exercise or a GLP-1 improved sperm count ^[4].

How does planning differ by situation?

For people who do not want pregnancy, clinicians counsel effective contraception before starting a GLP-1 [1, 2]. For people who do want pregnancy, the label-recommended washout — 2 months for semaglutide, 1 month for tirzepatide — is something to plan with a provider [6, 5]. For those already pregnant, the guidance is to stop and contact a provider [2, 3].

One tension worth knowing: higher-weight women are often told to lose weight before a fertility workup, and those delays matter because ovarian reserve falls with age, as Santoro and Merhi note ^[4].

Sources

1. Cleveland Clinic. ‘Ozempic Babies’: How GLP-1 Agonists Affect Fertility. March 10, 2025.
2. Endocrinology Advisor. GLP-1s and Fertility.
3. GoodRx. Ozempic Babies? What Research Says About Semaglutide & Fertility.
4. National Geographic. Is there really an Ozempic baby boom? The unexpected ways GLP-1s could influence fertility. November 4, 2025.
5. Clue. How GLP-1 Medications Like Ozempic Might Affect Your Birth Control.
6. Novo Nordisk. Wegovy prescribing information.
7. PubMed Central. Pregnancy Outcomes After Semaglutide Exposure.
8. News-Medical. GLP-1 exposure in pregnancy does not clearly raise major birth defect risk. July 10, 2026.
9. PubMed Central. Periconceptional use of GLP-1 receptor agonists and the risk of major congenital malformations: a systematic review and meta-analysis.
10. PubMed Central. Periconceptional GLP-1 receptor agonist exposure and obstetric outcomes: a Danish nationwide cohort study.
11. PubMed Central. Unintentional periconceptional exposure to glucagon-like peptide-1 receptor agonists and adverse pregnancy outcomes: A nationwide cohort study in Taiwan.
12. PubMed. Impact of semaglutide exposure on fetal and neonatal outcomes in pregnant women: a systematic review.
13. Urology. Impact of GLP-1 Receptor Agonists on Male Fertility: Emerging Evidence and Future Directions. July 2026.
14. Endocrine Society. Clinical trials suggest GLP-1s may improve fertility in men with obesity. June 13, 2026.
15. Medical News Today. How GLP-1 drug semaglutide may play a role in reproductive health.