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

Gynecol Endocrinol. 2015;31(11):833-9. doi: 10.3109/09513590.2015.1041906. Epub 2015 Oct 6.


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.

Keywords: Metformin; miscarriage; polycystic ovary syndrome; pregnancy complications; premature birth.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Abortion, Spontaneous / epidemiology
  • Case-Control Studies
  • Diabetes, Gestational / epidemiology
  • Female
  • Humans
  • Hypoglycemic Agents / therapeutic use*
  • Incidence
  • Metformin / therapeutic use*
  • Polycystic Ovary Syndrome / drug therapy*
  • Pre-Eclampsia / epidemiology
  • Pregnancy
  • Pregnancy Complications / drug therapy*
  • Pregnancy Complications / epidemiology
  • Premature Birth / epidemiology


  • Hypoglycemic Agents
  • Metformin