MONDAY, April 15, 2019 (HealthDay News) -- In pregnant women with polycystic ovary syndrome (PCOS), metformin treatment from the late first trimester until delivery might reduce the risk for late miscarriage and preterm birth but does not prevent gestational diabetes, according to a study published in the April issue of The Lancet Diabetes & Endocrinology.
Tone S. Løvvik, Ph.D., from the Norwegian University of Science and Technology in Trondheim, and colleagues conducted a randomized trial to evaluate whether metformin prevents late miscarriage and preterm birth in women with PCOS. Women aged 18 to 45 years were randomly assigned to receive either metformin (244 participants; 500 mg twice daily the first week, which was increased to 1,000 mg twice daily) or placebo (243 participants) until delivery.
The researchers found that the composite primary outcome of late miscarriage and preterm birth occurred in 5 percent of women in the metformin group and 10 percent of women in the placebo group (odds ratio, 0.5; 95 percent confidence interval, 0.22 to 1.08; P = 0.08). There were no significant differences between the groups for secondary end points, including incidence of gestational diabetes (odds ratio, 1.09; 95 percent confidence interval, 0.69 to 1.66; P = 0.75). Further, there were no substantial differences between the groups with respect to serious adverse events in either mothers or offspring. The principal investigators did not consider any serious adverse events to be drug-related. In a post-hoc meta-analysis of individual participant data from this study plus two previous randomized controlled trials, 5 percent of 397 women had late miscarriage or preterm delivery in the metformin group versus 10 percent of 399 women in the placebo group (odds ratio, 0.43; 95 percent confidence interval, 0.23 to 0.79; P = 0.004).
"Perhaps the most remarkable finding was that metformin had no effect whatsoever on either the incidence or severity of gestational diabetes," a coauthor said in a statement.
The study was funded in part by the Novo Nordisk Foundation, and one author disclosed financial ties to the pharmaceutical industry.