Continuation of Metformin Reduces Early Pregnancy Loss in Obese Pakistani Women with Polycystic Ovarian Syndrome

Background: Polycystic ovarian syndrome (PCOS) is the most common cause of anovulatory infertility worldwide. In addition to a poor conception rate, pregnancy loss rates are significantly higher (30–50%) during the first trimester in women with PCOS. Insulin resistance (IR) in this syndrome is not only implicated toward early pregnancy loss (EPL) but also pathognomic for various obstetrical complications during pregnancy. We evaluated the role of Metformin in the reduction of EPL in women with PCOS who conceived spontaneously or after induction ovulation with or without Metformin. Objective: The primary objective was to evaluate the effectiveness of Metformin in the reduction of EPL in women with PCOS. Secondary outcomes like gestational diabetes, pregnancy-induced hypertension and intrauterine growth restriction were also analyzed at the end of the study. Material and Methods: This case-control study was conducted from March 2005 to March 2008 in the infertility and antenatal clinics of the Department of Obstetrics and Gynecology of Aga Khan University Hospital, Karachi, Pakistan. A total of 197 infertile women with PCOS were included. ‘Cases’ were women with PCOS who conceived while taking Metformin and it whom it was continued throughout pregnancy. ‘Controls’ were women in whom Metformin was either stopped in first trimester after confirmation of pregnancy (by serum βHCG or by ultrasound) or they conceived spontaneously without the use of Metformin. Results: All 197 women in this study had a confirmed diagnosis of PCOS (Rotterdam criteria). These women were followed till the final outcome of pregnancy was achieved. Both groups were compared for risk of EPL. It was found that continuation of Metformin during pregnancy reduces EPL, i.e. 8.8 vs. 29.4% in cases and controls, respectively (p < 0.001). In the subset of women with a prior history of miscarriage, the pregnancy loss rate was 12.5% in the Metformin versus 49.4% in control group (p = 0.002). Conclusion: Metformin continuation during pregnancy significantly reduces EPL in women with PCOS. IR may play a significant role in EPL.