Metformin during assisted reproduction in women with PCOS

This study explored the impact of the drug metformin (Glucophage) on women with polycystic ovary syndrome (PCOS) who were undergoing assisted reproductive techniques (treatments to get pregnant). The study concluded that there was no firm evidence that birth rates increased by using metformin. 

PCOS is a condition where a woman’s hormones are out of balance. Insulin (a hormone) levels are often high in women with PCOS. High insulin levels can cause the ovaries to produce testosterone (a male hormone). This can result in infertility. Metformin is a treatment that decreases insulin levels. Metformin is also thought to prevent ovarian hyperstimulation syndrome (OHSS; painful, swollen ovaries). Whether metformin can improve birth rates and reduce OHSS is unclear. 

This study reviewed the results from 9 clinical trials (816 women) to assess whether metformin had an effect on pregnancy rates, live birth rates, and OHSS. Studies compared the effect of metformin to a placebo (substance with no effect on the body) or to no treatment at all. All women were undergoing treatment to get pregnant.

The odds of achieving pregnancy were 52% higher in women treated with metformin. However, there was no significant difference in live birth rates. The risk of OHSS was 71% lower in the metformin-treated patients. Mild gastrointestinal side effects were much more common in the patients taking metformin. 

The study concluded that in women with PCOS, metformin before or during assisted reproduction treatments significantly reduced the risk of OHSS. While pregnancy rates were higher, there was no firm evidence of an increase in live births. 

This was an analysis of multiple studies. Methods were not consistent among the trials.