Diabetes Obes MetabSide Effects & SafetyCohortDecember 5, 2025

Unintentional periconceptional exposure to glucagon-like peptide-1 receptor agonists and adverse pregnancy outcomes: A nationwide cohort study in Taiwan.

Chou YC, Weng SH, Cheng FS, Tseng CH, Hu HY, Liu CH

Key Finding

Among 160 women with diabetes who accidentally used GLP-1 medications around conception, there were no increased risks of birth defects, stillbirth, preterm birth, or small babies compared to insulin users.

What This Study Found

This study is like having a nationwide safety net that caught an unexpected situation - what happens when women with diabetes accidentally take GLP-1 medications (like Ozempic or Mounjaro) around the time they get pregnant? Researchers in Taiwan tracked down 3,351 pregnancies from women with pre-existing diabetes, finding 160 who had been prescribed GLP-1 drugs during the critical 90-day window around conception (45 days before and after their last period). Think of this timeframe as the 'construction zone' when a baby's organs are being built - any medication exposure here could theoretically cause problems. The researchers played matchmaker, pairing each GLP-1-exposed pregnancy with 4 similar insulin-using pregnancies to make a fair comparison. The results were reassuring: GLP-1 exposure didn't increase the risk of major birth defects, stillbirths, premature births, or having unusually small babies. It's like comparing two groups of construction projects - both had similar rates of structural problems, timing issues, and final building sizes.

Statistics Decoded

Risk ratio of 0.64 for malformations means GLP-1 users actually had slightly fewer birth defects than insulin users (though this could easily be chance - the confidence interval of 0.11-3.83 is so wide it includes both major protection and major harm). The stillbirth risk ratio of 2.05 sounds scary but isn't statistically significant - it's like seeing 2 extra stillbirths per 100 pregnancies, but the confidence interval (0.82-5.13) means the real number could be anywhere from slightly protective to 5 times worse. Preterm birth risk was nearly identical (1.09 ratio), and small baby risk was slightly lower (0.86 ratio). The study matched 160 GLP-1 users with 606 insulin users after propensity scoring - like creating two groups that look identical on paper except for their diabetes medication.

Why This Matters

This provides the first real-world safety data for women who accidentally used GLP-1 medications early in pregnancy, offering reassurance that immediate panic isn't warranted - though the authors still recommend against intentional use during pregnancy planning until larger studies confirm these preliminary findings.

Original Abstract

To assess whether periconceptional exposure to glucagon-like peptide-1 receptor agonists (GLP-1 RAs) is associated with adverse outcomes in women with pregestational type 2 diabetes. We linked Taiwan's Birth Certificate Application and National Health Insurance claims (2013-2022) to assemble a nationwide cohort of singleton births to mothers (18-50 years) with pregestational diabetes. Exposure was any GLP-1 RA dispensed during the 90 days before and after the last menstrual period; insulin without GLP-1 RA was the active comparator. Outcomes were major congenital malformations, stillbirth, preterm birth (<37 weeks) and small for gestational age (SGA, <10th percentile). We used 1:4 propensity-score matching and Poisson generalised estimating equation (GEE); sensitivity analyses required ≥2 prescriptions and restricted exposure to the first trimester. We identified 3351 comparison pregnancies (GLP-1 RA 160; insulin 3191); matching yielded 160 versus 606. Risk ratios (GLP-1 RA vs. insulin) were malformations 0.64 (95% confidence interval 0.11-3.83), stillbirth 2.05 (0.82-5.13), preterm birth 1.09 (0.85-1.39) and SGA 0.86 (0.31-2.41). Sensitivity analyses were similar. Periconceptional GLP-1 RA exposure was not associated with increased risks of malformations, stillbirth, preterm birth or SGA versus insulin use. These preliminary data require confirmation in larger agent-specific studies; until then, intentional GLP-1 RA use in planned pregnancy is not advised.