Dr. Michael P. Diamond of Wayne State University in Detroit, Dr. Richard S. Legro of the Pennsylvania State College of Medicine in Hershey and researchers at 16 institutions in the National Institute of Child Health and Human Development Cooperative Reproductive Medicine Network said polycystic ovary syndrome is a disorder in which the ovaries, and sometimes the adrenal glands, produce excess amounts of hormones.
Women with the disorder typically have menstrual irregularities and may have difficulty getting pregnant.
Infertility treatment for the condition typically involves ovulation induction -- drug treatment to stimulate the release of an egg, but before ovulation induction, physicians often use a single course of progestin, which leads to a thickening in the lining of the uterus.
The idea behind the treatment is to simulate the bleeding that occurs at the beginning of the monthly menstrual cycle, Diamond explained.
However, women who skipped the progestin before receiving fertility drugs were four times more likely to conceive than were women given the hormone.
In addition, 20 percent of the women who did not receive progestin gave birth, compared with about 5 percent of the women who received progestin.