Metformin may help women with polycystic ovary syndrome (PCOS) achieve pregnancy

Metformin, a drug used to treat diabetes and once thought to have great promise in overcoming the infertility linked to polycystic ovary syndrome (PCOS), is less effective than the standard fertility drug therapy, clomiphene. As per scientists from the University of Pennsylvania School of Medicine and the National Institutes of Health Reproductive Medicine research network, this is the largest, most comprehensive effort yet to compare the two drugs in helping PCOS patients achieve successful pregnancy. PCOS affects seven to eight percent of women in the United States and may be the most common cause of female infertility. With PCOS, an excess of male hormones interfere with ovulation and cause the ovaries to enlarge and fill with cysts. Women with PCOS frequently experience insulin resistance, a pre-diabetic condition in which higher-than-normal amounts of insulin are mandatory to allow glucose to enter tissues. Earlier studies had shown that drugs such as metformin which make the body more sensitive to insulin could increase ovulation in PCOS patients. Similarly, several smaller studies had suggested that metformin, alone or when taken together with the drug clomiphene, could result in greater fertility rates for PCOS patients than could clomiphene alone. Clomiphene fosters ovulation by stimulating the release of hormones needed for ovulation to occur. Scientists recommend and support the use of clomiphene alone and NOT in combination with Metformin as a first-line treatment for infertility in women with PCOS. As per the study authors, women who took metformin ovulated more that the women who were given the standard therapy. Similarly, women in the combination treatment group ovulated more frequently than did the women in either the clomiphene-alone or the metformin-alone groups. However, as the current study revealed, an increase in ovulation did not result in more successful pregnancies and deliveries for either the metformin alone, or combination group. To conduct the study, the scientists randomly assigned 626 infertile women with PCOS to one of three groups. The first group received clomiphene and a placebo. The second group received metformin and a placebo, and the third group received both metformin and clomiphene. The women took the medicine for up to six months. The scientists tested the women's levels of the hormone progesterone to gauge when the women were ovulating.

The scientists observed that fewer women in the metformin only group had given birth than had women in either of the clomiphene groups. In the metformin only group, 15 out of 208 women had given birth, or 7.2 percent. In the clomiphene only group, 47 out of 209 women had given birth, or 22.5 percent. In the combined clomiphene-metformin group, 56 out of 209 women had given birth (26.8 percent). The difference in the number of births between the clomiphene only group and the combined clomiphene-metformin group was not statistically significant. The scientists also observed that, in comparison to the other women in the study, obese women were less likely to conceive during the course of the study and less likely to ovulate in response to metformin. The study authors also noted that while metformin alone did not improve the chances for pregnancy, it was useful for lowering the high blood testosterone levels that occur with PCOS.