Treatment of Diabetes in Pregnancy With Metformin.

Metformin is a commonly used drug in the treatment of type 2 diabetes and has been used to treat gestational diabetes since the 1970s. In pregnancy, its proven benefits include reduced gestational weight gain and reduced fetal size; some studies have shown reduced risk of cesarean delivery and lower rates of hypertension. Metformin can reduce the need for insulin therapy but does not eliminate such need in many patients. Despite these benefits, metformin crosses the placenta and has been associated with increases in the risk of giving birth to small-for-gestational-age neonates in some studies of individuals with type 2 diabetes in pregnancy. In addition, higher body mass index (BMI) z-scores have been observed among exposed offspring in some of the long-term follow-up studies. Nevertheless, metformin's low cost, ease of administration, and global reach make it a reasonable intervention in a population affected by rising rates of obesity and diabetes in pregnancy. Further follow-up studies are required to monitor the long-term health of exposed offspring.