Figure. Recruitment, Randomization, and Assessment in a Trial of Prenatal Intravenous Magnesium for Imminent Preterm Birth.

^aThere was stratification by hospital site, gestational age (30-31 weeks’ gestation and 32-33 weeks’ gestation), and the number of fetuses (1 or 2).

^bFor the secondary outcomes, 858 infants (729 pregnant individuals) were included for the assessments prior to hospital discharge and 837 children (710 pregnant individuals) were included for the assessments at 2 years’ corrected age. Surviving children were assessed as close as possible to 2 years’ corrected age by a pediatrician and an assessor trained to administer the third edition of the Bayley Scales of Infant Development (BSID-III). For the sensitivity analysis, which incorporated data from all sources (pediatrician, psychometrist, caregiver questionnaires, and caregiver), there were 823 children (697 pregnant individuals). For the adverse events and other secondary outcomes, 729 pregnant individuals were included.

^cFor the secondary outcomes, 821 infants (704 pregnant individuals) were included for the assessments prior to hospital discharge and 796 children (679 pregnant individuals) were included for the assessments at 2 years’ corrected age. Surviving children were assessed as close as possible to 2 years’ corrected age by a pediatrician and an assessor trained to administer the BSID-III. For the sensitivity analysis, there were 785 children (670 participants). For the adverse events and other secondary outcomes, 704 pregnant individuals were included.