In a recent study published in the New England Journal of Medicine, Syngelaki and colleagues studied the effect of metformin use in obese pregnant women without diabetes. Obesity in pregnant women can increase adverse events for both the mother and the baby and lifestyle changes do not seem to have a strong impact on the likelihood of these events. In this study, the patients in the study were given either metformin or a placebo pill. During the follow-up visits, the researchers obtained vitals such as weight, blood pressure, and urinanlysis for proteins and ketones. They were also interviewed to monitor adherence and episodes of nonadherence were documented. The primary outcome measured in this study was the difference between the infant’s expected birth weight given gestational age and the actual birth weight, also known as the median neonatal birth-weight z score. One of the secondary outcomes measured in the study was gestational weight gain.
The data obtained from the study showed no significant difference in the median neonatal birth-weight z score. There was also not difference in the number of “large-for-gestational-age neonates” or the number of adverse events for the mother or the fetus. In fact, the metformin group had the same number of adverse events and a larger number of side effects. Overall, the study used information from previous publication that suggest that higher pregnancy BMI and increase weight gain during pregnancy increase the prevalence of complications such as preeclampsia. Results from this study suggest that prophylactic 3 mg dose of metformin during the second trimester of pregnancy decreased gestational weight gain but did not have an effect on the median neonatal birth weight.
I found this study to be very interesting because the obesity rates in the United States are high relative to other countries and this obesity rate impacts many different health determinants. This study to me was particularly interesting because it was looking at obese women without diabetes, who also can develop adverse complications during pregnancy. The study was well-designed, using an ethnically diverse population and sampling from three different hospitals. The results were supported by other previously published literature and it was an important topic of research given that lifestyle and diet modifications do not reduce obesity-related complications during pregnancy.