Huhtala MS, et al. - In this study, the effects of metformin and insulin treatment on maternal serum lipids were compared in patients with gestational diabetes (GDM), and to examine the relationships between individual lipids and birth weight (BW). Researchers designed a secondary analysis of a randomized trial to compare metformin (n=110) and insulin (n=107) treatment of GDM. They assessed fasting serum lipidome at baseline (the time of diagnosis, mean 30 gestational weeks, gw) and at 36 gw applying nuclear magnetic resonance spectroscopy. The data revealed that metformin treatment of GDM led to higher maternal serum concentrations of triglyceride-rich lipoproteins in comparison with insulin. In VLDL, particularly triglycerides and cholesterol were positively correlated with BW. The evidence suggested that women with high VLDL cholesterol or high apoB/apoA-1 may benefit from insulin treatment over metformin with respect to offspring BW.