Drug improves birth rates for women with ovary disorder

Polycystic ovary syndrome (PCOS) is a leading cause of female infertility. It affects five to 10 per cent of reproductive-age women. Women with PCOS have unusually high levels of male hormones, infrequent or irregular menstruation cycles, and oftentimes enlarged ovaries packed with fluid-filled cysts.

The current treatment for PCOS infertility is the drug clomiphene. It works by blocking estrogen action, which stimulates hormones that induce ovulation. However, clomiphene has multiple side effects, including hot flashes and mood changes. The drug’s 22 per cent success rate for live births is relatively low, and it tends to lead to a high number of twin or multiple pregnancies.

In a search for more effective ways to reverse PCOS infertility, some physicians have begun using the drug letrozole. Letrozol has been approved as a breast cancer treatment by the US Food and Drug Administration. The drug is also known to suppress production of estrogen, which in turn triggers release of the hormones that drive ovulation.

A multicentre clinical study led by Dr Richard S Legro of Penn State College of Medicine compared the effectiveness of letrozole and clomiphene in treating PCOS-related infertility. The effort was funded in part by NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and National Centre for Advancing Translational Sciences (NCATS). Results were published recently in the New England Journal of Medicine.

The researchers enrolled 750 infertile women with PCOS who were between 18 and 40 years of age. All participants were attempting to achieve pregnancy, and their male partners met minimum sperm count requirements. The participants were randomly divided into two groups to receive either letrozole or clomiphene. Women were given up to five monthly cycle treatments.

The researchers found that women treated with letrozole were more likely to have live births than those receiving clomiphene (27.5 per cent vs. 19.1 per cent). Letrozole also led to significantly increased ovulation rates compared to clomiphene (61.7 per cent vs. 48.3 per cent).

EP News Bureau – Mumbai