The data for this analysis were taken from the baseline (enrollment) assessment. Maternal demographic characteristics and obstetrical events at the index birth were summarized by breastfeeding initiation status at first delivery. Continuous variables were summarized using median and interquartile range (IQR); categorical variables were summarized using percent and frequency. Differences by breastfeeding status in the distribution of maternal demographic and clinical characteristics at first delivery were tested using Kruskal–Wallis tests for continuous variables and Fishers’ Exact Chi-square tests for categorical variables.