GLP-1 Receptor Agonists in Pregnancy: What the Evidence Shows

Abstract

Obesity in reproductive-age women is associated with increased risk of cardiometabolic disease, infertility, and pregnancy-related complications affecting both the mother and fetus. The introduction of highly effective glucagon-like peptide-1 (GLP-1) receptor agonists has led to increased utilization of obesity medications in this population. While these agents are not recommended during pregnancy, their use in the preconception, periconception, and postpartum periods is increasing. Data on their safety and clinical utility during these reproductive windows remain limited. This review summarizes the current literature on the risks and benefits of GLP-1 receptor agonist use for both the mother and fetus, highlights key clinical considerations across reproductive stages, emphasizes the primacy of human exposure data where available, and identifies critical evidence gaps requiring future prospective study.

Study at a Glance

Study Snapshot

Study Facts Table

What Researchers Actually Did

Porterfield and colleagues conducted a narrative scoping review of peer-reviewed literature on GLP-1 receptor agonist use in reproductive-age women, searching PubMed and Embase for publications from January 2015 through January 2026. Search terms combined MeSH headings and keywords spanning GLP-1 receptor agonists, anti-obesity medications, pregnancy, preconception, periconception, postpartum, lactation, maternal obesity, and fetal outcomes. They included human studies of all designs — case series, observational cohorts, and systematic reviews — and incorporated animal data only when human data were absent or insufficient, clearly flagging each as such. Studies focused solely on glycemic management without meaningful pregnancy exposure data were excluded.

The review was explicitly narrative rather than systematic. The authors acknowledged that the heterogeneity and scarcity of available evidence precluded meta-analysis. Their stated purpose was to synthesize clinically relevant data to inform counseling and decision-making in reproductive-age individuals using obesity pharmacotherapy, not to produce a definitive quantitative estimate of risk. The review covers four discrete clinical windows: preconception, periconception, active pregnancy, and postpartum including lactation, and it examines both maternal and fetal outcomes within each.

Key Findings: Primary Outcomes

• Major congenital anomalies (largest cohort): In a retrospective cohort of 3,514,865 pregnancies (Cesta et al.), early GLP-1 RA exposure (n = 938) was not associated with an increased risk of major congenital anomalies among live-born infants compared with insulin-treated pregnancies (n = 5,078); adjusted risk ratio 0.95 (95% CI 0.72–1.26).
• Major congenital malformations (prospective observational cohort): In 168 pregnancies with early GLP-1 RA exposure, no increased risk of congenital malformations was observed versus a diabetic reference group (n = 156; adjusted OR 0.98; 95% CI 0.16–5.82) or an overweight/obese reference group (n = 163; adjusted OR 0.54; 95% CI 0.11–2.75).
• Pregnancy loss (same prospective cohort): Early GLP-1 RA exposure was not associated with increased pregnancy loss versus the diabetic reference (adjusted HR 1.67; 95% CI 0.93–3.01) or the overweight/obese reference (adjusted HR 0.80; 95% CI 0.48–1.33).
• Semaglutide first-trimester case series: Morton and colleagues reported 13 confirmed cases of semaglutide exposure in the first trimester; one infant exhibited significant congenital anomalies, but the mother had poorly controlled type 2 diabetes and hypertension, precluding attribution to the drug.
• Maternal mortality and hypertensive disorders: Hanif et al. found no increased risk of maternal mortality, gestational hypertension, preeclampsia, or eclampsia associated with first-trimester GLP-1 RA exposure.

Key Findings: Secondary Outcomes and Subgroup Analyses

• Preconception GLP-1 RA use and obstetric outcomes (Imbroane et al.): A retrospective observational study reported that preconception GLP-1 RA exposure was associated with lower risk of gestational diabetes, hypertensive disorders of pregnancy, preterm delivery, and cesarean delivery. The authors acknowledge retrospective design and limited sample size as major constraints on these findings.
• Conflicting preconception data (Maya et al.): A separate observational study using granular patient-level clinical and laboratory data found that individuals with GLP-1 RA exposure prior to and during early pregnancy experienced greater gestational weight gain and had higher risks of excess GWG, preterm delivery, gestational diabetes, and hypertensive disorders of pregnancy — findings directly contradicting those of Imbroane et al.
• PCOS and reproductive parameters: GLP-1 RAs have been shown to restore normal menstruation and improve reproductive parameters in women with PCOS; improvements in pregnancy rates or live births have not been demonstrated in formal clinical studies, and GLP-1 RA use is not recommended for the fertility indication alone.
• Prepregnancy BMI as a predictor: A meta-analysis of nearly 200,000 pregnancies found prepregnancy BMI to be a stronger predictor of adverse maternal and neonatal outcomes than gestational weight gain, underscoring the preconception window as the highest-yield intervention period.
• Semaglutide in breast milk: A small pharmacokinetic study found no detectable semaglutide levels in human milk within 24 hours of dosing. The oral bioavailability of semaglutide is reported to be less than 1%, making clinically meaningful infant systemic exposure theoretically unlikely even if ingested via breast milk.

Results: Adverse Events and Safety Profile

Animal reproductive toxicity studies of GLP-1 RAs have documented increased rates of embryofetal loss, reduced fetal weight, and structural abnormalities. These effects occurred at doses exceeding the maximum recommended human dose and were associated with significant maternal weight loss and caloric restriction, creating uncertainty about whether observed harms reflect direct drug toxicity, maternal undernutrition, or species-specific pharmacology. In human first-trimester exposure data, no consistent teratogenic signal has emerged, but the data are drawn from retrospective and small prospective cohorts with meaningful potential for residual confounding and selection bias. The safety profile of continued GLP-1 RA use during the second and third trimesters is effectively uncharacterized in humans. Abrupt discontinuation carries its own risk profile: rapid weight regain and worsening glycemic control have been documented in non-pregnant populations following cessation of semaglutide and tirzepatide, and these metabolic perturbations in the periconceptional period may elevate risk of early pregnancy loss, GDM, and preeclampsia. During lactation, appetite suppression from GLP-1 RAs may reduce caloric intake in a period of increased nutritional demand, with downstream potential for reduced milk supply and altered breast milk composition.

Statistical Approach and Rigor

This is a narrative scoping review; no original statistical analysis was conducted by the authors. The statistical figures cited derive entirely from the included primary literature, each with distinct analytic approaches, reference populations, and confounders. The confidence intervals reported for the key congenital anomaly and pregnancy loss estimates are wide, reflecting small exposed sample sizes. The adjusted risk ratio of 0.95 (95% CI 0.72–1.26) from the largest study carries an upper bound that does not exclude a clinically meaningful harm. The prospective cohort ORs (0.98, CI 0.16–5.82; 0.54, CI 0.11–2.75) are statistically uninformative given interval width. The narrative format precludes pooled effect estimation and means all conclusions must be interpreted as qualitative synthesis of heterogeneous data rather than quantitative meta-analytic evidence.

Why This Matters Clinically

GLP-1 receptor agonists are among the most rapidly adopted pharmacotherapy classes in modern medicine, and women of reproductive age constitute a substantial portion of the user population. Given that GLP-1 RAs reduce body weight by 15–21% on average in clinical trials and confer meaningful cardiometabolic benefits, their use in the preconception period to optimize maternal metabolic health before pregnancy has clear mechanistic rationale. At the same time, obesity itself carries a 3- to 4-fold elevation in GDM and preeclampsia risk, nearly doubles cesarean delivery odds, and increases postpartum infection risk by more than threefold. The clinical dilemma is acute: clinicians are managing patients on effective cardiometabolic medications in a population with high background disease burden, limited medication alternatives, and a growing body of evidence that is directionally inconsistent. The stakes are compounded by data showing that prepregnancy BMI is a stronger predictor of adverse maternal and neonatal outcomes than gestational weight gain — meaning that the preconception window may represent the single highest-yield opportunity for risk reduction, precisely when the most effective pharmacotherapy must currently be discontinued.

CED Clinical Relevance

At CED Clinic, where patients using cannabis-adjacent or cannabinoid-based therapies often carry concurrent cardiometabolic diagnoses including obesity and type 2 diabetes, the intersection of GLP-1 RA pharmacotherapy with reproductive planning is a real and growing clinical scenario. Many patients in this population are women of reproductive age who are actively managing obesity with semaglutide or tirzepatide. This review’s findings reinforce the need for proactive reproductive counseling in all such patients: identifying pregnancy intent early, establishing a structured discontinuation plan with a minimum two-month washout before planned conception, implementing nutritional support, and arranging close metabolic monitoring after cessation. The conflicting observational data on preconception use also reinforce that clinicians should not assume either continued use or abrupt discontinuation is the lower-risk path — both carry documented or plausible harms.

Fits What We Already Know

The review situates its findings within a well-established literature on obesity’s adverse reproductive consequences. Prior bariatric surgery data, cited by the authors, demonstrate that intentional preconception weight loss reduces gestational diabetes, preeclampsia, and emergency cesarean delivery risk. Preconception glycemic optimization in type 2 diabetes, per cited meta-analyses, reduces congenital malformation rates, preterm delivery, and neonatal ICU admissions. The behavioral economics of gestational weight gain are similarly established: approximately 50% of pregnant individuals exceed recommended targets, rates are higher among those with obesity, and clinicians frequently fail to provide guideline-concordant counseling. The epigenetic literature cited — linking maternal hyperglycemia to leptin gene methylation changes and maternal obesity to altered placental adipokine regulation — provides biological plausibility for why preconception metabolic optimization may have transgenerational relevance. The pattern that emerges from the review’s cited evidence base is that the preconception period has historically been underprioritized in clinical practice, and that GLP-1 RAs represent a new and powerful but incompletely studied tool for addressing that window.

What This Study Teaches Us

The most honest synthesis of this review is that the field is at a very early stage. Human data on GLP-1 RA exposure during pregnancy are expanding but remain anchored in retrospective cohorts, pharmacovigilance databases, and small prospective series — data sources that are structurally incapable of detecting subtle teratogenic signals or characterizing second- and third-trimester risks. The review teaches clinicians that the two key questions they face in practice — whether to continue GLP-1 RAs until conception and whether inadvertent early exposure warrants alarm — have different answer structures: on inadvertent early exposure, available data are modestly reassuring; on optimal preconception timing and discontinuation strategy, the evidence is conflicting and insufficient. It also teaches that postpartum weight retention is common, that GLP-1 RAs are an increasingly used tool in that period, and that lactation data are early but suggest minimal infant drug exposure from semaglutide specifically.

What It Does Not Show

• This review does not demonstrate that GLP-1 RAs are safe to use during pregnancy; the absence of a detected teratogenic signal in first-trimester data cannot be extrapolated to the second or third trimesters.
• It does not resolve whether preconception GLP-1 RA use improves or worsens pregnancy outcomes; two observational studies with conflicting findings are cited, and neither is definitive.
• It does not establish that semaglutide is safe during breastfeeding; the pharmacokinetic study showing undetectable drug levels was small, short in follow-up, and assessed only a single agent.
• It does not address long-term offspring outcomes, including neurodevelopment, childhood metabolic health, or risk of obesity, following GLP-1 RA exposure at any reproductive stage — the authors explicitly note that prospective studies on these endpoints are absent.
• It does not provide comparative efficacy or safety data across different GLP-1 RA agents in reproductive contexts; most human pregnancy case data involve shorter-acting agents such as liraglutide and exenatide.
• It does not address tirzepatide (a dual GIP/GLP-1 agonist)
  
  Evidence Watch Reading Tool

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  The same evidence can produce very different conclusions depending on the question being asked. Explore this study through multiple physician-guided interpretive frameworks.

  OVERVIEW

  Review of GLP-1 RA use across reproductive stages highlights insufficient evidence and critical gaps.

  OverviewWhy this paper matters
  Patient TakeawayReal-world implications
  Clinician’s POVClinical decision-making
  A Skeptical ReadAlternative explanations
  Study CriticMethodology audit
  Compared to Past ResearchHistorical context
  Practical ConsiderationsImplementation barriers
  Future DirectionsWhat comes next
  Misreadings & Bad-Faith TakesCommon distortions

  Overview

  Badge 1: ComprehensiveBadge 2: Evidence-BasedBadge 3: Reproductive Stages

  This review synthesizes the current literature on GLP-1 receptor agonist use across preconception, pregnancy, and postpartum periods. It highlights key clinical considerations and identifies critical evidence gaps requiring future prospective study.

  While no consistent signal of major congenital malformations has been identified in human first-trimester exposure data, the evidence base remains insufficient to justify reassurance across all reproductive windows.

  • No consistent teratogenic signal from first-trimester GLP-1 RA exposure.
  • Evidence gaps exist for second and third trimesters and lactation safety.
  • Conflicting observational data on preconception use demand further study.

  Key Insight

  GLP-1 RA use in pregnancy remains controversial due to limited human data.

  Patient Takeaway

  Badge 1: Patient-CentricBadge 2: Risk-Benefit AnalysisBadge 3: Individualized Care

  Patients should be informed about the limited human data on GLP-1 RA use during pregnancy and postpartum. Clinicians should consider individual risks and benefits, including potential metabolic perturbations from abrupt discontinuation.

  Preconception use may offer some benefits in reducing gestational diabetes risk but also poses risks of increased gestational weight gain.

  • Discuss individual risks and benefits with healthcare providers.
  • Consider preconception use for potential pregnancy outcome improvements.
  • Be aware of metabolic risks from abrupt discontinuation.

  Patient Advice

  Discuss GLP-1 RA use in pregnancy with your healthcare provider.

  Clinician’s POV

  Badge 1: Clinical GuidanceBadge 2: Evidence SynthesisBadge 3: Risk Management

  Clinicians should prioritize human exposure data and consider individual patient risks and benefits across preconception, pregnancy, and postpartum periods. The safety profile of continued use during lactation is uncharacterized.

  Prepregnancy BMI is a stronger predictor of adverse outcomes than gestational weight gain, underscoring the importance of early intervention.

  • Prioritize human exposure data in decision-making.
  • Consider individual patient risks and benefits.
  • Be cautious about lactation safety.

  Clinical Guidance

  Use GLP-1 RAs with caution during pregnancy and postpartum.

  A Skeptical Read

  Badge 1: Critical ThinkingBadge 2: Evidence EvaluationBadge 3: Skeptical Inquiry

  Skeptics should critically evaluate the limited human data on GLP-1 RA use during pregnancy and postpartum. Conflicting observational data on preconception use demand further study to draw firm conclusions.

  The safety profile of continued use during lactation is uncharacterized, adding to the uncertainty surrounding these medications in reproductive-age women.

  • Critically evaluate limited human data.
  • Demand further prospective studies for preconception use.
  • Question lactation safety.

  Skeptical Perspective

  Approach GLP-1 RA use in pregnancy with caution and skepticism.

  Study Critic

  Badge 1: Critical AnalysisBadge 2: Evidence CritiqueBadge 3: Scientific Rigor

  Critics should highlight the insufficient prospective studies, confounding factors, and lack of data on second and third trimester use and lactation safety. The review underscores the need for more rigorous scientific investigation to establish a clearer risk-benefit profile.

  Conflicting observational data on preconception GLP-1 RA use demand further study before firm clinical conclusions can be drawn.

  • Highlight insufficient prospective studies.
  • Critique confounding factors in existing research.
  • Demand more rigorous scientific investigation.

  Critical Analysis

  Call for more robust evidence on GLP-1 RA use in pregnancy.

  Compared to Past Research

  Badge 1: Historical ContextBadge 2: Evolution of ResearchBadge 3: Past Findings

  Past research has shown increased embryofetal loss, reduced fetal weight, and structural abnormalities in animal studies at supratherapeutic doses. However, these findings may not translate to humans.

  Human data on GLP-1 RA use during pregnancy are limited and confounded, with no consistent teratogenic signal identified from first-trimester exposure.

  • Animal studies showed increased embryofetal loss at supratherapeutic doses.
  • No consistent teratogenic signal in human first-trimester data.
  • Human data remain limited and confounded.

  Historical Context

  Past research highlights the need for more human data on GLP-1 RA use.

  Practical Considerations

  Badge 1: Practical AdviceBadge 2: Real-World ApplicationBadge 3: Clinical Practice

  Practically, clinicians should recommend at least 2 months of GLP-RA discontinuation before conception to minimize potential risks. Prepregnancy BMI is a stronger predictor of adverse outcomes than gestational weight gain.

  GLP-1 RAs can restore normal menstruation and improve reproductive parameters in women with PCOS, but they are not recommended for fertility alone.

  • Recommend at least 2 months discontinuation before conception.
  • Prepregnancy BMI is a stronger predictor of adverse outcomes.
  • Use GLP-1 RAs cautiously in women with PCOS.

  Practical Advice

  Recommend discontinuation and consider individual risks.

  Future Directions

  Badge 1: Future DirectionsBadge 2: Research NeedsBadge 3: Emerging Trends

  Future research should focus on prospective studies to address the critical evidence gaps identified in this review. Studies should aim to clarify the safety profile of GLP-1 RAs during second and third trimesters and lactation.

  Further investigation is needed to resolve conflicting observational data on preconception use and pregnancy outcomes.

  • Focus on prospective studies for critical evidence gaps.
  • Clarify safety profile during second and third trimesters.
  • Resolve conflicting preconception data.

  Future Research

  Call for more prospective studies on GLP-1 RA use.

  Misreadings & Bad-Faith Takes

  Badge 1: Common MisunderstandingsBadge 2: Clarification NeededBadge 3: Correct Interpretation

  Common misinterpretations include assuming no risk based on limited human data and overestimating the benefits of preconception GLP-RA use. Clinicians should be cautious about lactation safety.

  Conflicting observational data on preconception use demand further study to avoid incorrect conclusions.

  • Avoid assuming no risk from limited data.
  • Be cautious about lactation safety.
  • Resolve conflicting preconception data.

  Misreadings

  Avoid common misinterpretations of GLP-1 RA use.

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  What is the current evidence on GLP-1 RA use in pregnancy?

  No consistent signal of major congenital malformations has been identified in human first-trimester exposure data, but the evidence base is limited and confounded.

  Are there any risks associated with continuing GLP-1 RA use during pregnancy?

  Continued use may introduce metabolic risk, including rapid weight regain and worsening glycemic control post-discontinuation.

  What about the safety of GLP-1 RAs in breast milk?

  No detectable semaglutide levels were found in human milk within 24 hours of dosing, suggesting minimal risk to infants.

  How does preconception GLP-1 RA use affect pregnancy outcomes?

  Studies show conflicting results; some suggest lower risks of gestational diabetes and hypertensive disorders, while others report increased gestational weight gain.

  What is the recommended discontinuation window for GLP-1 RAs before conception?

  Experts recommend at least 2 months prior to conception to minimize potential risks.

  Are there any benefits of using GLP-1 RAs in women with PCOS?

  GLP-1 RAs can restore normal menstruation and improve reproductive parameters, but they are not recommended for fertility alone.

  What does the evidence say about GLP-1 RA use in the postpartum period?

  The safety profile of continued use during lactation is uncharacterized, but appetite suppression may reduce caloric intake.

  How do animal studies inform our understanding of GLP-1 RA risks in pregnancy?

  Animal studies show increased embryofetal loss and structural abnormalities at supratherapeutic doses, but these findings may not translate to humans.

  What are the key clinical considerations for GLP-1 RA use in reproductive-age women?

  Clinicians should prioritize human exposure data and consider individual patient risks and benefits across preconception, pregnancy, and postpartum periods.

  What are the critical evidence gaps identified in this review?

  The review highlights insufficient prospective studies, confounding factors, and lack of data on second and third trimester use and lactation safety.