Metformin may improve PCOS uterine receptivity

Conclusions: metformin therapy corrected ovulatory function to a similar extent to that seen with clomiphene citrate, but with a greater improvement in fertility and reproductive outcome. One interpretation of these findings is that metformin may have a specific effect on uterine receptivity 

Metformin therapy appears to improve surrogate markers of uterine receptivity in certain women with polycystic ovary syndrome (PCOS), research reveals.

In a recent randomized controlled trial, metformin therapy corrected ovulatory function to a similar extent to that seen with clomiphene citrate, but with a greater improvement in fertility and reproductive outcome. One interpretation of these findings is that metformin may have a specific effect on uterine receptivity.

To test this hypothesis, Stefano Palomba (University 'Magna Graecia' of Catanzaro, Italy) and colleagues studied uterine vascularization, endometrial thickness, and endometrial pattern in 37 anovulatory PCOS patients, who were given metformin for 6 months, and in 30 age-matched controls.

Before treatment, uterine, sub-endometrial, and endometrial blood flows were significantly lower in the PCOS patients than in controls. However, each of these measures improved significantly during treatment in PCOS women who began to ovulate, reaching levels similar to those found in controls.

No significant differences in any of the parameters measured were seen between PCOS patients with favorable and those with unfavorable reproductive outcomes, but Palomba et al say this lack of difference could be due to the low number of patients in the latter group.

They conclude: "Further data are necessary to explain the exact mechanism by which metformin exerts its beneficial effects on the uterus."

Human Reproduction 2006; 21: 457-65

Evaluating the uterine effects of metformin in patients with polycystic ovary syndrome who ovulated during treatment.

Posted: 24 January 2006