Relationship between the time to delivery after the first course of betamethasone and the incidence of severe (grades 3 and 4) intraventricular hemorrhage. Among the 667 infants in the study population, 28 died before 4 days and before the highest grade of intraventricular hemorrhage could be determined: n=8, in the group that delivered ≤6 hours from the initiation of BMZ; n=2, in the group that delivered between 7 and 23 hours; n=3, in the group that delivered between 24 and 47 hours; n=12, in the group that delivered between 48 hours and 7 days; n=0, in the group that delivered between 8 and 9 days; n=3, in the group that delivered 10 days or more after a single course of BMZ; and, n=0, in the group that delivered after a second/rescue course of BMZ.