THURSDAY, Feb. 28, 2002 (HealthDayNews) -- One of the most popular pills to treat diabetes appears to dramatically reduce the risk of miscarriage in women with ovarian cysts linked to pregnancy problems.
Earlier research has shown that the drug, metformin, can improve the odds of conception in women with polycystic ovary syndrome (PCOS). However, the latest work, which appears in the current issue of the Journal of Clinical Endocrinology and Metabolism, shows it may also increase their chances of a successful pregnancy once they've conceived.
Polycystic ovary syndrome is a leading cause of female infertility and miscarriage, which occurs in 30 percent to 50 percent of pregnancies in women with the condition. The disorder affects 5 percent to 10 percent of American women of reproductive age. It is characterized by cysts in the ovaries that are egg follicles in a state of arrested development, unable to ovulate.
One feature of PCOS is high blood levels of insulin, the hormone that lets cells turn sugar in the blood into energy. Metformin -- sold under the brand name Glucophage -- makes cells more sensitive to the hormone, but experts say why it might prevent miscarriages is a mystery.
Some evidence suggests that in addition to improving the body's response to insulin, the drug may also increase blood flow to the uterus and make the womb more hospitable to the developing fetus.
Many women with PCOS also have elevated male sex hormones, or androgens, potentially disturbing fertility. Too much insulin is believed to promote androgen production, so metformin may also ease that problem.
In addition to reproductive complications, the cysts are linked to a wide range of health problems, including obesity, high blood pressure, hardened arteries, and, because of the added male hormones, abnormally heavy body and facial hair.
Since women with PCOS don't ovulate regularly, they often seek fertility treatment. Scientists have been using metformin, which was approved for the treatment of diabetes in 1994, to give ovulation drugs a boost.
The new study, by researchers in the United States and Venezuela, was a retrospective look at 96 women with PCOS, 65 of whom had taken metformin to help them ovulate. There were 68 pregnancies in the group that received the drug. Six of them -- roughly 9 percent -- ended in miscarriage during the first three months of pregnancy.
However, 13 of the 31 pregnancies -- 42 percent -- among the women who didn't get the diabetes drug aborted prematurely. In other words, women who took metformin were 4.5 times less likely to lose their fetuses in the first trimester.
When the researchers studied the drug among a smaller group of women with a history of miscarriage, they found it to be even more protective, reducing the risk more than fivefold.
One baby whose mother took metformin developed a birth defect, called achondrodysplasia, a form of dwarfism. However, whether that was the result of the drug isn't clear.
Louis DePaolo, a program officer at the National Institute of Child Health and Human Development, which funded the research, said that for a relatively small study the magnitude of risk reduction was impressive.
"If it was 10 percent versus 20 percent, I'd say forget it. But my guess is that even if it turns out to be a two- or threefold change, that's going to be highly significant in terms of treatment," DePaolo says.
DePaolo cautions that since the study was retrospective, it must be considered preliminary. The institute is now weighing whether to fund a trial with metformin to look specifically at whether it cuts the risk of miscarriage in women with ovary problems.
Dr. Mark Perloe, medical director of Georgia Reproductive Specialists, a fertility clinic in Atlanta, says the findings "make sense from a scientific standpoint," and the results are "certainly the case that we have seen here." However, he also warned that it's tricky to draw conclusions from retrospective studies.
What's more, Perloe says, there's disagreement in the medical community about which women should be treated for ovary cysts. Some clinics are more liberal in their view of when to treat the syndrome, while others are more conservative.
What To Do
To find out more about polycystic ovary syndrome, try the University of Cincinnati or Georgia Reproductive Specialists.
To learn more about metformin, try the National Institute of Diabetes and Digestive and Kidney Diseases.
