Takeaway
- Use of metformin for any indication during pregnancy was associated with a reduction in gestational weight gain (GWG) and a modest reduction in the risk of pre-eclampsia, but an increased risk of gastrointestinal (GI) side effects compared with other treatments.
- No significant effects were observed on other maternal outcomes.
Why this matters
- Despite the widespread use of metformin during pregnancy, limited data is available on maternal outcomes in metformin users.
Study design
- UK researchers conducted a meta-analysis of 35 randomised controlled trials (RCTs) including 8033 participants.
- Funding: None.
Key results
- Metformin vs other treatment group had:
- reduction in GWG (mean difference, 1.55 kg; 95% CI, -2.14 to -0.95; P<.00001; I2, 86%); and
- lower risk of pre-eclampsia (OR, 0.69; 95% CI, 0.50-0.95; P=.02; I2, 55%).
- No significant difference was seen between metformin and other treatment group in the risk of:
- gestational hypertension (P=.66);
- preterm birth (P=.47);
- gestational age at delivery (P=.29);
- emergency caesarean section (P=.47) and elective caesarean section (P=.14);
- gestational diabetes mellitus development (P=.52); and
- fasting blood glucose level (P=.63) and random blood sugar level (P=.11).
- Metformin vs other treatment group was associated with an increased risk of GI side effects (OR, 2.43; 95% CI, 1.53-3.84; P=.0002; I2, 76%).
Limitations
- Heterogeneity among studies.
This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.
