Am J Obstet Gynecol

Metformin continuation in early pregnancy linked to better outcomes in PCOS

June 18, 2025

Study details: This systematic review and meta-analysis evaluated 12 randomized trials involving 1,708 women with polycystic ovary syndrome (PCOS). The studies compared pregnancy outcomes in women who began metformin preconception and either continued it through the first trimester or discontinued it upon pregnancy confirmation. Outcomes assessed included miscarriage (primary), clinical pregnancy, and live birth rates.

Results: Preconception metformin continued through the first trimester was associated with a higher clinical pregnancy rate (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.11–2.23), a possible reduction in miscarriage (OR, 0.64; 95% CI, 0.32–1.25), and a possible increase in live birth (OR, 1.24; 95% CI, 0.59–2.61) compared with placebo or no treatment. Stopping metformin at pregnancy confirmation increased clinical pregnancy rates (OR, 1.35; 95% CI, 1.01–1.80) but showed a non-significant trend toward increased miscarriage (OR, 1.46; 95% CI, 0.73–2.90). Indirect comparisons favored continuation through the first trimester for all outcomes.

Clinical impact: Continuing metformin through the first trimester in women with PCOS may improve clinical pregnancy rates and reduce miscarriage risk compared with stopping at pregnancy confirmation. These findings support the potential benefit of ongoing metformin therapy during early pregnancy, but further high-quality research is needed to confirm these effects and inform clinical guidelines.

Source:

Cheshire J, et al. (2025, June 3). Am J Obstet Gynecol. Preconception and first trimester metformin on pregnancy outcomes in women with polycystic ovary syndrome: a systematic review and meta-analysis. https://pubmed.ncbi.nlm.nih.gov/40473092/