Progestin treatment for PCOS may decrease likelihood of pregnancy, birth
Women treated with progestin for polycystic ovarian syndrome were four times less likely to become pregnant, based on findings from a study conducted by the NIH research network.
Michael P. Diamond, MD, of Wayne State University School of Medicine, and Richard S. Legro, MD, of Penn State College of Medicine, collaborated with researchers at 16 institutions in the National Institute of Child Health and Human Development (NICHD) Cooperative Reproductive Medicine Network.
The research team conducted a secondary analysis of the 2007 data from 626 women with PCOS from the Eunice Kennedy Shriver NICHD Cooperative Reproductive Medicine Network trial. The patients were randomly assigned to up to six cycles of clomiphene citrate alone, metformin alone or clomiphene citrate plus metformin.
“Among all the cycles with ovulation, conceptions occurred in 4.5% and 6.6% of the cycles that were preceded by spontaneous menses and anovulatory cycles with progestin withdrawal,” the researchers wrote. “In contrast, the conception rate was dramatically increased (27.7%) in the cycles with anovulation without progestin withdrawal (P<.001).”
Additionally, 72% of patients ovulated the following month, and about 5% were able to conceive.
In an accompanying editorial, Robert F. Casper, MD, said the study was a “surprising and important discovery,” which could prompt a change in the way the field currently addresses the management of infertility in women with anovulation secondary to PCOS.
Casper is a professor in the division of reproductive sciences at the University of Toronto; Camille Dan Family Research chair in translational cell biology; and senior scientist at the Samuel Lunenfeld Research Institute at Mount Sinai Hospital. He is also medical director at the Toronto Centre for Advanced Reproductive Technology.
“There were only 19 conceptions (12 live births) in nearly 1,000 cycles of metformin use alone, so it is also possible that an apparent negative effect of endometrial shedding on a pregnancy outcome with metformin alone might have been a spurious finding,” Casper said. “In any event, the observation of a negative effect of endometrial shedding seems to be clear in the clomiphene citrate cycles, with or without metformin added.”
He said a prospective study with detailed follow-up, including ultrasound monitoring of the endometrium, should be initiated to confirm the findings of this study.
- Casper RF. Obstet Gynecol. 2012;119:886-887.
- Diamond MP. Obstet Gynecol. 2012;119:902-908.
- Legro RS. N Engl J Med. 2007;356:551-566.
- Dr. Diamond is a consultant for EMD Serono. Drs. Legro and Casper report no relevant financial disclosures.