Gestational diabetes & diabetes in pregnancy
Metformin in High Metabolic Risk Pregnancies — A Patient-Level Meta-Analysis
Authors' conclusion
In this IPD meta-analysis, metformin was not associated with a reduction in GDM, but was associated with an increase in gestational age at delivery.
Study context
- Population
- Pregnancies without diabetes (high metabolic risk)
- Participants
- 2,297 pregnancies10 trials
- Comparison
- Metformin vs placebo
- Metforminn = 1,159
- Placebon = 1,138reference
- Outcome
- Maternal: GDM and OGTT glycemic indices; neonatal: gestational age at delivery and neonatal anthropometry
Methodological detailsdouble-blind, placebo-controlled trials, one-stage mixed-effects models, adjusted for maternal age, BMI, gestational age at commencement and baseline blood glucose, Databases searched through May 9, 2025
- Double-blind
- Placebo-controlled trials
- One-stage mixed-effects models
- Adjusted for maternal age, BMI, gestational age at commencement and baseline blood glucose
- Databases searched through May 9, 2025
Pooled result
As reported in the abstract
GDM
Each group vs placeboEstimate (95% CI)
Metformin
OR (WHO 1999 criteria) 1.04(0.80–1.36)
Metformin
aOR (WHO 1999 criteria) 1.00(0.71–1.41)
Metformin
OR (NICE 2015 criteria) 0.98(0.76–1.27)
Metformin
aOR (NICE 2015 criteria) 1.00(0.71–1.41)
Metformin
OR (IADPSG thresholds) 0.83(0.65–1.06)
Metformin
aOR (IADPSG thresholds) 0.71(0.52–0.98)
Each group vs placeboMD (fasting blood glucose), mmol/l (95% CI)
Metformin
−0.06(−0.10 to −0.01)
Each group vs placeboMD (gestational age at delivery), weeks' gestation (95% CI)
Metformin
0.30(0.06–0.54)
Each group vs placeboMD (neonatal head circumference), percentile (95% CI)
Metformin
2.43(0.13–4.72)
Further pooled results
| Outcome | aOR (95% CI) | |
|---|---|---|
| Preterm birth | 0.64 (0.47–0.89) | |
| 0.512Adjusted odds ratio (log scale) |
Safety
- Gastrointestinal side effects more commonly reported with metformin
Original publication
Metformin in High Metabolic Risk Pregnancies — A Patient-Level Meta-Analysis. NEJM Evid. Published 25 August 2026. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →