According to a new study published in the January 22 issue of the New England Journal of Medicine, more extremely premature U.S. infants — those born after only 22–28 weeks of gestation — are surviving.
“Understanding the causes and timing of death in extremely premature infants may guide research efforts and inform the counseling of families,” wrote Ravi Mangal Patel, MD, an assistant professor of pediatrics at the Emory University School of Medicine in Atlanta, and colleagues.
Patel and colleagues analyzed data from 6,075 deaths among more than 22,248 live births with gestational ages of 22–28 weeks. The births occurred between 2000– 2011. The babies were followed from birth for 120 days, or until they died, left the hospital, or were transferred to another hospital. Infants hospitalized for more than 120 days were evaluated until they died or until they turned 1 year.
During the study period, the death rate for extremely premature infants dropped by nearly 10%. Overall, 40.4% of the deaths happened within 12 hours after birth. Another 17.3% happened after 28 days. The largest declines in mortality were in those born at 23 or 24 weeks of gestation. The decrease in deaths from breathing complications made up 53% of the overall reduction in mortality. Deaths from infections and nervous system problems also dropped, but deaths from necrotizing enterocolitis increased. Deaths within the first 12 hours after birth were mostly from immature development of body systems. Deaths after 12 hours were mostly from respiratory distress syndrome. Deaths from 15–60 days after birth were largely due to necrotizing enterocolitis, and deaths after 60 days were mostly from bronchopulmonary dysplasia.
“Although our study demonstrates that overall survival has improved in recent years among extremely premature infants, death still remains very high among this population,” Patel told HealthDay. “Our findings underscore the continued need to identify and implement strategies to reduce potentially lethal complications of prematurity. Ultimately, strategies to reduce extremely preterm births are needed to make a significant impact on infant mortality.”
— Vimala McClure