A study led by Richard Legro and published in New England Journal of Medicine compares letrozole and clomiphene drugs to see which is better in women affected by polycystic ovary syndrome who want to become pregnant.
The most commonly used drug in this group of women is clomiphene (Clomid). However, the success rate after 6 treatment cycles is lower (19%) compared to letrozole (27.5%). Besides, the rate of twin pregnancies is higher with clomiphene (6.9%) than with letrozole (3.9%). Also the side effects with letrozole are lower than with clomiphene. None of these drugs involves a risk to newborns.