Survival Rate for Early Preemies Climbs in US

By Emory University
Emory University
Emory University
September 10, 2015 Updated: September 10, 2015

Babies born extremely premature have shown modest increases in survival and reductions in neonatal complications in the last 20 years. Experts say changes in maternal and infant care may explain why.

Overall survival increased most significantly in infants born at 23-24 weeks, but survival without major health problems identified prior to hospital discharge increased most in infants 25-28 weeks. The study did find an increase in one complication of prematurity: bronchopulmonary dysplasia.

The review analyzed more than 34,000 deliveries of babies born at 22-28 weeks gestational age and 401 to 1500 grams birth weight between 1993 and 2012 in the United States. 

“This study is the first comprehensive NRN review to evaluate 20 years of changes in care practices, major health problems, and survival of extremely premature infants,” says Barbara Stoll, professor and chair of pediatrics at Emory University School of Medicine.

“Our findings show that progress is being made and outcomes are improving. This information should be valuable in counseling families and in developing new interventions to help prevent and treat significant health problems in these infants.”

Survival Rates

Changes in care of preterm infants over the 20 years include an increase in antenatal corticosteroid use, an increase in cesarean delivery, and a decrease in delivery room intubation. Between 2002 and 2012 there was an increase in continuous positive airway pressure without ventilation. The 1990s saw an increase in postnatal steroid use, followed by a decrease until 2004.

Although rates of most serious health problems declined, bronchopulmonary dysplasia increased between 2009 and 2012 for infants born at 26-27 weeks but did not change significantly for infants born at 22-25 or 28 weeks. The authors note a decrease in late-onset sepsis between 2005 and 2012.

Overall survival to discharge increased between 2009 and 2012 for infants born at 23 weeks (27 percent to 33 percent) and for infants born at 24 weeks (63 percent to 65 percent), with smaller relative increases in survival for infants born at 25 and 27 weeks, and no change for infants born at 22, 26, and 28 weeks.

Survival to discharge without major health problems increased approximately two percent per year for infants born at 25-28 weeks, with no change for infants born at 22-24 weeks.

Maternal hypertension increased from 12 to 27 percent, and maternal insulin-dependent diabetes increased from 2 to 5 percent. A major birth defect was reported for 1,292 infants (3.7 percent), with no significant change in percentage over 20 years. The percent of infants from a multiple birth increased from 18 percent in 1993 to 27 percent in 1998, with no further increase during the study period. Infants in the study were 52 percent male.

“Our analysis shows that survival of extremely premature infants and survival without major health problems have improved over 20 years,” Stoll says. “One of our most important new findings is a significant increase in survival without major neonatal health problems for infants born at 25-28 weeks.

“We will continue to seek even better strategies for long-term health, particularly reducing brain injury and promoting healthy neurodevelopment. At the same time, we must focus on reducing the high rates of preterm birth, with approximately 450,000 infants born prematurely in the United States each year.”

The findings appear in the Journal of the American Medical Association.

This article was previously published by Emory University.  Republished via under Creative Commons License 4.0.