The standard treatment for helping such women is a drug called clomiphene citrate, which stimulates the ovary to grow eggs. But a significant number of infertile women do not ovulate even when given this drug. When clomiphene citrate didn't work in the past, the only option was injections of pituitary hormones called gonadotropins, which directly stimulate egg production. It also is very time-consuming because women have to be monitored with blood tests and ultrasound every few days. Gonadotrophins also raise the risk of multiple births and can overstimulate the ovaries.
Some evidence suggests that clomiphene-resistant women are resistant to insulin.
So if their insulin processing could be improved, maybe they would ovulate in response to standard doses of clomiphene citrate. The researchers are testing metformin because it increases the body's sensitivity to insulin. Ratts is heading the St. Louis portion of a trial that also is taking place at the Medical College of Virginia and the University of Virginia. Each site will enroll 33 patients. Half of the women in the study will take metformin, and the other half will receive an inactive substance.