Data and samples.
ADVERSE EVENTS, STERILE
We collected detailed data on mothers, including demographics, medical history, anthropometrics, and medication use, including antibiotics during pregnancy. Data collected for the infants included demographics, method of first feeding and subsequent feedings, medication use, and adverse events. We collected and managed study data using the REDCap electronic data capture tools hosted at the Inova Health System.For this study, maternal samples collected and analyzed were as follows: (i) prenatal maternal stool from after 35 weeks gestation, (ii) vaginal swab collected just prior to the vaginal gauze insertion before randomization, (iii) gauze used for swabbing the neonate, (iv) skin swab from the forearm obtained the day after delivery, and (iv) buccal swab obtained the day after delivery. Infant samples collected and analyzed were as follows: (i) transitional stool sample at day of life 2 to 3, (ii) stool sample around day 30 of life (mean, 34.9 days [SD 3.73]), and (iii) skin swab from the forearm (using a dry sterile swab rolled over forearm skin area of approximately 2 by 2 inches) obtained the day after delivery before the infant’s first bath. We stored all samples at −80°C until analysis.