Metformin reduces preterm births, late miscarriages in PCOS

CHICAGO – When women with polycystic ovary syndrome (PCOS) took metformin during pregnancy, preterm births and late miscarriages were reduced, but researchers saw no effect on blood glucose levels or other diabetes-related maternal outcomes.

A Nordic study of pregnant women, dubbed PregMet 2, followed the course of 487 women with PCOS who were randomized to take 2,000 mg of metformin or placebo daily during pregnancy.

^{Kari Oakes/MDedge News}

Dr. Tone Løvvik

Among the entire study population, those with PCOS who took placebo had a 9.6% incidence of late miscarriage or preterm birth. For those taking metformin, the figure was 5%, similar to the 5.2% risk seen in the population-wide Norwegian Birth Registry, said Dr. Løvvik, of the Norwegian University of Science and Technology, Trondheim.

This analysis yielded a number needed to treat (NNT) for benefit of metformin of 22, she said.

However, Dr. Løvvik said that “the elephant in the room” is the lack of benefit of metformin for rates of gestational diabetes, hypertension in pregnancy, or preeclampsia in PregMet 2.