Kim JA, Kim J, Roh E, et al. - Researchers conducted this nationwide population-based cohort study to explore the connection between pre-pregnancy triglyceride-glucose (TyG) index and gestational diabetes mellitus (GDM) in primipara women. In total, 380,208 women who underwent a Korean national health screening exam within 2 years before their first delivery, between January 1, 2012, and December 31, 2015, were involved. In participants aged ≥ 35 years, with obesity, with impaired fasting glucose, who are current smokers, and with a family history of diabetes mellitus, the impact of a high TyG index on the risk of GDM was more profound. Findings suggested an association of increased pre-pregnancy TyG index with a risk of GDM. Elevation of the TyG index can be an early GDM marker.