The high MD trajectory between the age of 3 and 8 was negatively associated with TNF-α cord serum levels (adjusted Odds Ratio (aOR) = 0.35, 95%CI [0.18–0.67]), adjusting on the mother's pre-pregnancy BMI category, maternal risk of clinical depression at 6 months pregnant, smoking and alcohol consumption during pregnancy, delivery mode, gestational age at birth and the child's sex on imputed data. This evidence concerns the gene TNF and major depressive disorder.