Effects of metformin-diet intervention before and throughout pregnancy on obstetric and neonatal outcomes in patients with polycystic ovary syndrome

Curr Med Res Opin. 2013 Jan;29(1):55-62. doi: 10.1185/03007995.2012.755121. Epub 2012 Dec 12.


Objective: Prospectively assess whether metformin/diet pre-conception and throughout pregnancy would safely reduce first trimester miscarriage and improve pregnancy outcomes in women with polycystic ovary syndrome (PCOS).

Research design and methods: In 76 PCOS women, first pregnancy miscarriage and live birth were compared before and on metformin/diet, started 6.8 months (median) before conception, continued throughout pregnancy. On metformin 2-2.55 g/day, low glycemic index diet, first pregnancy outcomes in PCOS were compared with 156 community obstetric practice women (controls).

Main outcome measures: Live births, miscarriage, birth <37 weeks gestation, gestational diabetes, pre-eclampsia, fetal macrosomia.

Results: In 76 PCOS women before metformin-diet, there were 36 miscarriages (47%) and 40 live births vs. 14 (18%) miscarriages and 62 live births on metformin-diet 6.8 months before conception and throughout pregnancy, p = 0.0004, OR 3.99, 95% CI 1.91-8.31. On metformin-diet, PCOS women did not differ (p > 0.08) from controls for birth <37 weeks gestation, gestational diabetes, pre-eclampsia, or fetal macrosomia.

Conclusions: Metformin-diet before and during pregnancy in PCOS reduces miscarriage and adverse pregnancy outcomes. Study limitation: individual benefits of the diet alone and diet plus metformin could not be assessed separately. Randomized, controlled clinical trials now need to be done with a larger number of patients.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abortion, Spontaneous / etiology
  • Abortion, Spontaneous / prevention & control
  • Adult
  • Diabetes, Gestational / etiology
  • Diabetes, Gestational / prevention & control
  • Female
  • Fetal Macrosomia / etiology
  • Fetal Macrosomia / prevention & control
  • Humans
  • Hypoglycemic Agents / administration & dosage*
  • Live Birth*
  • Metformin / administration & dosage*
  • Polycystic Ovary Syndrome / therapy*
  • Pre-Eclampsia / therapy
  • Pregnancy
  • Prospective Studies


  • Hypoglycemic Agents
  • Metformin