Polycystic ovarian syndrome, or PCOS, is a disorder involving excess levels of androgen hormones. Typically, women with PCOS have many small cysts in their ovaries, and eggs fail to mature properly.
Infertility caused by PCOS is usually treated with clomiphene (Clomid), a drug that stimulates egg production. But letrozole (Femara), a breast cancer drug not approved for inducing ovulation, may be a better choice. (Both drugs are also sold in generic versions.)
A study, published in the July 10, 2014, issue of The New England Journal of Medicine, randomized 750 infertile women with PCOS to one or the other of the two drugs. They went through up to five treatment cycles.
After controlling for fertility history, race, various blood hormone levels and other factors, the researchers found that ovulation, conception and pregnancy were all significantly higher in the women who took letrozole.
There was little difference in side effects or serious adverse events, and women on letrozole were 44 percent more likely to deliver a baby.