Blais K, Arguin M, Allard C, et al. - In the Gen3G prospective birth cohort, researchers sought to examine correlations of maternal glycaemia at different periods in pregnancy with childhood adiposity and leptin levels at 5 years of age. They measured maternal glucose levels after a 50 g oral glucose challenge test at the first trimester (9.8 ± 2.3 weeks) and during a 75 g oral glucose tolerance test at the second trimester (26.5 ± 0.9 weeks) in a prospective pre‐birth cohort. Maternal glycaemia at the first trimester was linked to childhood leptin levels at 5 years, regardless of maternal pre‐pregnancy BMI and other confounders. Higher post‐load glucose levels at the second trimester were related to greater total body fat percentage measured by DXA, but not with leptin levels. The findings indicate that leptin regulation programming may be sensitive to maternal hyperglycaemia, especially in early pregnancy.