Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant

Department Chair

John Cavenagh, PhD, PA-C


OBJECTIVE: The objective of this selective EBM review is to determine “Does Metformin use during pregnancy effectively reduce the rate of early pregnancy loss in women with polycystic ovary syndrome?”

STUDY DESIGN: This review is based on two primary double-blind, randomized controlled trials and a prospective controlled trial that was not randomized or blinded to evaluate whether metformin, a medication used to manage PCOS, can also prevent early pregnancy loss in women with PCOS.

DATA SOURCES: All articles used were published in English, in peer-reviewed journals, and located through PubMed, OVID and COCHRANE databases..

OUTCOMES MEASURED: Each of the three trials included evaluated the effectiveness of metformin at preventing pregnancy loss and premature labor in patients with PCOS, as well as safety of administering the drug during pregnancy. Sohrabvand et al solely focused on early pregnancy loss, with other studies following pregnancy to term.

RESULTS: Two double-blind randomized controlled trials and one prospective controlled trial were included in this review. Results from the Vanky et al (2004) study demonstrated a 22.7% decrease in premature birth rate in metformin group as compared to control. Sohrabvan et al also presented a statistically significant decrease in current miscarriage rate in groups taking metformin up to 8 weeks and 12 weeks, of gestation (p = 0.008 and p = 0.002, respectively) as compared to previous miscarriage rate. Vanky et al (2010) analyzed a multicenter trial, but its results differed in that a statistically significant decrease in preterm labor could only be appreciated after a subgroup analysis was performed of participants deemed to have good and acceptable compliance (7.4% decrease, p = 0.03). The recommendation made in this last trial was not in favor of metformin usage due to a perceived
overall lack of benefit.

CONCLUSIONS: Two of the three trials in this review support the use of metformin during pregnancy in women with PCOS as means of preventing pregnancy loss or premature labor. Various factors, such as tighter monitoring throughout pregnancy, and inconsistencies in pre-pregnancy metformin intake could have affected the results within this patient population.