Efficacy of metformin on pregnancy complications in women with polycystic ovary syndrome: a meta-analysis

OBJECTIVE: To evaluate the efficacy of metformin administration throughout pregnancy on pregnancy-related complications in women with polycystic ovary syndrome (PCOS). STUDY DESIGN: MEDLINE and ScienceDirect were searched to retrieve relevant trials. The endpoint was the incidence of complications of pregnancy, gestational diabetes mellitus (GDM), pre-eclampsia (PE), miscarriage and premature birth included. RESULTS: Five studies with 502 PCOS patients with metformin administration throughout pregnancy and 427 controls who used metformin just to get conception were included in our meta-analysis. In study group, a significantly lower change of emerging miscarriage and premature birth was observed, the pooled relative risk (RR) was 0.32 (95% confidence interval (CI): 0.19-0.56) for miscarriage and 0.40 (95%CI: 0.18-0.91) for premature birth. No significant difference was demonstrated in emerging GDM and PE. CONCLUSIONS: Metformin therapy throughout pregnancy can reduce the RR of miscarriage and premature birth incidence in PCOS patients with no serious side effects.