Of the various endpoint analyses, “the most surprising and striking one is the absolute lack of effect on gestational diabetes in this high-risk population,” said Dr. Løvvik. “There’s not even a tendency towards effect. … Metformin had no effect on prevention, treatment, or the need for additional insulin, indicating it was actually as effective as placebo.”
Considering that “metformin is now a part of the standard treatment for gestational diabetes, according to many national guidelines, we think that it’s questionable that it’s never, ever been tested against placebo for this diagnosis,” said Dr. Løvvik.
Pregnant women with PCOS have an increased risk of complications, and metformin is often prescribed off label to attempt to address some of these complications. Some previous work had shown metformin to be helpful, but previous studies have been underpowered, said Dr. Løvvik.
PregMet 2’s protocol attempted to address the literature gap; over 3 years, it called for enrollment of 1,000 women in the first trimester of pregnancy, randomized 1:1 to receive metformin or placebo in pregnancy.