Diabetes Drug Helps Prevent Miscarriage
March 1, 2002 -- A popular diabetes drug may hold the key to motherhood for millions of women with the most common form of infertility. Miscarriage rates dropped dramatically among a group of women with polycystic ovary syndrome (PCOS) treated with the drug metformin.
Researchers say the drug, also known as Glucophage, is also highly effective in preventing gestational diabetes, a form of diabetes that is common in pregnant women with PCOS, and may be a better treatment than insulin for all women with pregnancy-related diabetes.
"This therapy is rapidly revolutionizing the treatment of infertility, and with good reason," says Charles Glueck, MD, who conducted some of the first metformin infertility studies and has treated almost 1,500 women with the syndrome. "In women with PCOS the risk of miscarriage is very high, around 50%. By giving metformin, the risk is reduced to that of a woman without PCOS."
It is believed that up to 10% of Caucasian women in the U.S., and 15% of Hispanic and black women have PCOS, although most have not been diagnosed. Women with the syndrome often have irregular or absent menstrual periods, elevated insulin levels (similar to people with type 2 diabetes), and weight problems. Many women with PCOS do not ovulate at all, and those who get pregnant often have miscarriages.
Metformin is approved for treating type 2 diabetes, but it is being used off-label by an increasing number of infertility specialists to treat PCOS-related infertility. Many doctors in the U.S. take women off the drug once they become pregnant, but the new research suggests they should keep taking it during pregnancy.
In a study published in the Journal of Clinical Endocrinology and Metabolism, researchers reviewed the histories of 65 pregnant women with PCOS who were taking metformin prior to conception and throughout their pregnancy and 31 pregnant women with PCOS who did not take the drug. The women were patients at a fertility clinic in Caracas, Venezuela, and they were treated over a four and a half year period.
Roughly 9% of the women who took the drug miscarried (six of 65), compared with 42% of women who did not (13 of 31). Among the women in each group who had a history of miscarriage, the rate of pregnancy loss was 11% for those receiving treatment and almost 60% for those not treated. The research was funded by the National Institute of Child Health and Human Development, a branch of the National Institutes of Health.
The study offers the best evidence yet that metformin may be useful for the treatment of gestational diabetes, says lead author John E. Nestler, MD, of the Medical College of Virginia. Insulin sensitivity improved for the pregnant women on metformin, compared with their sensitivity prior to pregnancy when not taking the drug.