As GLP-1 medications become more common for obesity and type 2 diabetes, more women and their clinicians are confronting questions the research cannot yet answer with confidence: When should treatment stop before pregnancy? What happens after an accidental exposure? Could the medications affect fertility or birth control? And when might treatment resume after delivery?
New international guidance offers a framework for navigating those decisions, but its central message is one of caution. Available human evidence has not identified a clear increase in major birth defects following accidental exposure around conception or early pregnancy. However, the research remains too limited to establish that GLP-1 medications are safe during pregnancy or breastfeeding.
The guidance, published in Obesity Reviews, was developed by experts from 23 institutions across Europe, North America and the Middle East. The authors reviewed 34 studies, including clinical trials, observational research, medication safety reports and case studies.
This was a systematic scoping review and expert consensus project, not a conventional meta-analysis that combined the results into a single estimate. The authors examined what is currently known, identified major gaps and developed practical recommendations for clinicians despite the limited evidence.
The review covered GLP-1 medications and related drugs used to manage obesity and type 2 diabetes. Their use has expanded rapidly among women of reproductive age, but pregnant and breastfeeding women have generally been excluded from clinical trials.
“The rapid adoption of GLP-1 medications has outpaced the evidence available for women who are planning pregnancy or become pregnant,” said Shahrad Taheri, a professor and vice dean for adiposity-based chronic diseases at the Marshall University Joan C. Edwards School of Medicine. “This work provides clinicians with up-to-date, evidence-informed guidance while highlighting urgent research priorities needed to ensure these therapies can be used as safely and effectively as possible in women of reproductive age.”
Current evidence does not support using the medications during pregnancy or breastfeeding. Women who are taking them and planning to become pregnant should talk with their prescribing clinician about when and how to stop treatment.
The appropriate timing may vary by medication because some drugs remain in the body longer than others. A patient’s individual health also matters, including whether the medication is being used to manage type 2 diabetes and how stopping it could affect blood sugar or weight.
The guidance also emphasizes the importance of birth control counseling. Weight loss and improved metabolic health may help restore regular ovulation in some women who previously had difficulty becoming pregnant, particularly those with obesity and polycystic ovary syndrome, or PCOS.
Pregnancy may therefore become possible even for someone who has experienced irregular menstrual cycles or infertility. The review found preliminary evidence that GLP-1 medications may improve some fertility-related outcomes before pregnancy among women with obesity or PCOS. However, they are not approved fertility treatments and should not be used during pregnancy.
The medications may also complicate the use of oral birth control in some circumstances. Tirzepatide carries specific advice about using another form of contraception temporarily when starting treatment or increasing the dose. Vomiting or severe diarrhea could also make birth control pills less reliable.
Recommendations vary by medication, so women should discuss contraception with a clinician or pharmacist rather than assume that the same advice applies to every GLP-1 drug.
Accidental exposure presents a more difficult question. The studies reviewed did not find a clear increase in major birth defects among pregnancies exposed near conception or during early pregnancy. That may offer some reassurance to women who discover they are pregnant while taking one of the medications, but it does not show that exposure is risk-free.
The number of documented pregnancies remains relatively small, and the available studies vary in quality. Researchers also lack enough information about miscarriage, fetal growth, premature birth, exposure later in pregnancy and children’s long-term development.
The guidance therefore does not support continuing GLP-1 medications during pregnancy. Instead, it gives clinicians a framework for counseling patients after an unintended exposure without assuming that harm has occurred or offering more reassurance than the evidence supports.
Evidence during breastfeeding is even more limited. Researchers do not yet know enough about whether the medications enter breast milk or how they might affect a nursing infant. The authors advise against their use while breastfeeding until stronger evidence becomes available.
Decisions about restarting treatment after delivery may depend on breastfeeding plans, blood sugar management, weight changes, recovery from pregnancy and whether another pregnancy is planned. The guidance recommends considering those circumstances individually rather than applying one timeline to every patient.
The review also makes clear how much remains unknown. The authors concluded that nearly half of the important clinical questions surrounding GLP-1 medications and reproductive health still cannot be answered adequately.
Many recommendations are therefore based on a combination of limited human research, what is known about the medications and expert consensus. The guidance should not be interpreted as proof that GLP-1 drugs are safe around pregnancy or as a substitute for individualized medical care.
The broader message is that pregnancy planning and contraception should become routine parts of conversations about GLP-1 treatment. Patients should not have to wait until they are trying to conceive or discover they are pregnant to receive that information.
Women should speak with their health care team before stopping or changing a prescribed medication. Suddenly ending treatment may create its own risks, particularly for someone taking it to manage type 2 diabetes.
The guidance gives clinicians a starting point, but the authors say prospective research and long-term follow-up are urgently needed to understand how these medications affect fertility, pregnancy, breastfeeding and children exposed before birth.
The review received no external funding. Michael Ceulemans’ broader research activities are supported by a postdoctoral mandate from the Research Foundation Flanders. Several authors reported speaking fees, consulting work, advisory roles, travel support or other relationships with pharmaceutical and medical technology companies, including manufacturers of GLP-1 medications. The authors stated that these relationships were outside this work.