New Drug Letrozole Increases Birth Rate Among women with PCOS

Scientists have found that fertility drug Letrozole increases the birth rate in women with Polycystic Ovary Syndrome (PCOS).

Polycystic Ovary syndrome (PCOS) is a common hormonal problem among women of the reproductive age and is also called hyperandrogenic anovulation. This endocrine disorder is linked with an excess of androgen or male hormone in the body due to which the patients have infrequent periods, develop cysts in ovaries and have trouble conceiving. This is the leading cause of infertility in women. It affects 5-10 percent of the women.

For decades, the standard treatment has been Clomiphene citrate - a drug known to stimulate ovulation. But, a new study led by the Penn state College of Medicine Researchers, found that the efficacy of letrozole was much better than the current infertility treatment drug. Letrozole belongs to a class of drug that blocks the production of estrogen.

"Clomiphene has its drawbacks," said Dr. Richard Legro, professor of obstetrics and gynecology and lead author on the study. "It's only 22 percent successful with up to six cycles of treatment in producing a successful birth, it has a high multiple-pregnancy rate in comparison to unassisted conception, and it has side effects including hot flashes and mood changes."

In this study, researchers compared the two drugs. They evaluated 750 infertile women with PCOS aged between 18-40 years, who wanted to conceive. These women were randomly given either clomiphene or letrozole and they were asked to take the medication for five cycles, with the dosage increasing with each cycle.

They noticed that the women taking letrozole had a higher rate of live births i.e. 27.5 percent, as compared to those taking clomiphene with just 19.1 percent. Also the rate of ovulation, at each monthly visit, was higher in those taking letrozole.

Among those taking letrozole, fewer twin pregnancies occurred. Intake of clomiphene led to higher rate of hot flashes and letrozole was linked to higher incidence of fatigue and dizziness. Birth defects were rare and rate was similar between the two medications.

The finding was documented in New England Journal of Medicine.