2.1. Study Design and Population
breast milk, substance abuse
GESTATIONAL DIABETES
The present report is a new component of a previously described clinical study [The inclusion criteria were as follows:singleton birth;gestational age 37 to 42 weeks;birth weight 2490 g;0 and 5 days of age at enrollment;exclusive formula or breastfeeding since birth;overall good health in the infant’s medical history and parental report;A resident of a smoke-free home.Exclusion criteria were the medical history of either the mother or child that might be considered to have potential developmental or growth effects including potential maternal substance abuse. Gestational diabetes was not considered exclusion criteria in cases where infant weight was within the 95th percentile [Infants whose parents intended to exclusively feed their infants formula were randomized to receive one of three formulas, all containing a total amount of 2.4 g/L of oligosaccharides, according to randomization schedules stratified by site and sex. A nonrandomized breastfed (BF) group was also enrolled. A flow diagram illustrating the study group assignments is given in ”Exclusively fed” was defined as the sole use of breast milk or assigned formula, and no other liquids or solids. An exception was made for the use of non-antibiotic prescriptions, mineral supplements, and vitamins. Occasional use of alternative feedings, defined as less than 5 times during the study period, was considered consistent with exclusive feeding.Participant selection for the substudy. Selection for the substudy was determined on the sole basis of parental or legal guardian authorization for the collection of blood samples. Participation in blood sample collection was entirely optional for all study participants