Comparison of pregnancy and neonatal outcomes
MAY
We compared participant characteristics, as recorded in the prospective data, stratified by the three pregnancy and neonatal outcome groups using Chi-squared tests among the 76 women enrolled in the pregnancy history survey. To compare pregnancy and neonatal outcomes in the two data sources, we included all pregnancy outcomes in the prospective data observed among the 76 enrolled women (which occurred between May 25, 2011, and May 25, 2017) and pregnancy outcomes reported in the pregnancy history survey that occurred during the prospective follow-up period for each participant plus 30 days before and after their observation. Specifically, this period was defined for each individual participant as the time from 30 days before their enrollment date in the prospective study and 30 days after either the last birth visit or last pregnancy surveillance visit (whichever was later) in the prospective study. This yielded an analytic dataset, referred to as the “complete dataset,” of 226 pregnancy outcomes, including 122 from the prospective data and 104 from the pregnancy history survey.