Metformin and Pregnancy
A prospective, randomized clinical trial comparing the effect of metformin on pregnancy outcomes in women undergoing in vitro fertilization (IVF)
Metformin is a medication traditionally used in diabetic patients to improve insulin sensitivity. Its applications have extended far beyond that limited patient population in recent years. Metformin use in in vitro fertilization (IVF) patients with polycystic ovary syndrome (PCOS) is now a common practice. Some studies have demonstrated higher clinical pregnancy rates when the medication is utilized. Others have shown no benefits in pregnancy or live birth rates but have demonstrated a decreased incidence of ovarian hyperstimulation syndrome. However, the effects of empiric metformin use by non-PCOS patients undergoing IVF have not been studied in a randomized fashion.
Basic science research has demonstrated improvements in embryo development and ovarian steroid production in the presence of metformin. The mechanism(s) of action are unclear at this time, but the end result may be improved pregnancy rates.
Metformin and IVF Research
We are currently testing the hypothesis that the administration of metformin to women undergoing IVF may improve multiple outcomes including egg and embryo quality and pregnancy rates. In a retrospective review of 125 ovulatory, non-PCOS patients (mean age 34.9 ± 3.9 years) undergoing a repeat IVF cycle with the administration of metformin ER (1500 mg/day), we found that pregnancy rates were statistically significantly increased across multiple groups. This data was presented at the American Society for Reproductive Medicine annual meeting in 2009. Additionally, a group out of Tokyo, Japan, recently demonstrated that the administration of low dose metformin (500mg/day) to women undergoing repeat IVF cycles improved pregnancy rates in a significant fashion. Thus, we hypothesize that the administration of metformin to patients undergoing IVF will improve pregnancy rates and that this improvement may be due to enhanced egg and embryo quality.
We have an ongoing randomized controlled trial in women undergoing their first IVF cycle to see if metformin actually does improve pregnancy rates.