Adjusted odds ratios of <6 months (a), 6–14 months (b) and 15–23 months (c) antibiotic exposure for overweight and obesity at 38 months and 7 years. 95% confidence intervals represented in lines, and point estimate represented as bullet. All multivariable models included birth weight, maternal parity, race, social class, education, parental BMI (categorized as mother pre-pregnancy overweight/obese, father overweight/obese and both overweight/obese), first trimester smoking, breastfeeding (categorized as never/breastfed cessation before 6 months/continuous breastfeeding through 6 months), timing of introduction of complementary foods, time spent per day watching television, in car on weekdays, in car on weekends, dietary pattern classifications at 38 months and duration of nighttime sleep at 7 years.