['To determine the extent to which known prenatal and perinatal predictors of childhood obesity also predict weight gain in early infancy.', 'We studied 690 infants participating in the prospective cohort Project Viva. We measured length and weight at birth and at 6 months. Using multivariable linear regression, we examined relationships of selected maternal and infant factors with change in weight-for-length z-score (WFL-z) from 0 to 6 months.', 'Mean (standard deviation) change in WFL-z from 0 to 6 months was 0.23 (1.11), which translates to 4500 grams gained from birth to 6 months of life in an infant with average birth weight and length. After adjustment for confounding variables and birth weight-for-gestational age z-score (-0.28 [95% confidence interval, -0.37, -0.19] per unit), cord blood leptin (-0.40 [95%confidence interval, -0.61, -0.19] per 10 ng/mL), and gestational diabetes -0.50 [95%confidence interval, -0.88, -0.11] versus normal glucose tolerance)were each associated with slower gain in WFL-z from 0 to 6 months.'] Do gestational glucose tolerance and cord blood leptin levels predict slower weight gain in early infancy?