Cause and Timing of Death According to
Gestational Age
Immaturity was most commonly identified as
the cause of death for infants born at 22 or 23
weeks of gestation; most of these infants died
within 12 hours after birth and were not intubated
in the delivery room (Table 3, and Table S7 in the
Supplementary Appendix). In contrast, deaths
among infants born at 24 to 27 weeks of gestation
were primarily attributed to the respiratory
distress syndrome; the majority of deaths among
these infants occurred from 12 hours to 28 days
of age, but more than 20% of deaths occurred
after 28 days of age (Table 4). As gestational age
increased, the percentage of deaths attributed to
necrotizing enterocolitis and congenital anomalies
also increased. The largest absolute declines
in mortality from 2000–2003 to 2008–2011 were
observed for infants born at 23 or 24 weeks of
gestation (Table 4).