Outcomes improve for extremely preterm infants

Advances in medicine over the past 2 decades have changed care for mothers in preterm labor and for extremely preterm infants. Evaluation of current in-hospital complications and mortality data among extremely preterm infants is important in counseling families and considering new interventions to improve outcomes. Barbara J. Stoll, M.D., of the Emory University School of Medicine, Atlanta, and colleagues reviewed trends in maternal/neonatal care, complications, and mortality among 34,636 infants, 22 to 28 weeks' gestation, birth weight of 14.1 ounces to 3.3 lbs. born at 26 Neonatal Research Network centers between 1993 and 2012.

The researchers found that survival increased between 2009 and 2012 for infants at 23 weeks' gestation (27 percent to 33 percent) and 24 weeks (63 percent to 65 percent), with smaller relative increases for infants at 25 and 27 weeks' gestation, and no change for infants at 22, 26, and 28 weeks' gestation. Survival without major complications increased approximately 2 percent per year for infants at 25 to 28 weeks' gestation, with no change for infants at 22 to 24 weeks' gestation.

"Perhaps the most important new finding is a significant increase in survival without major neonatal morbidity [complication] for infants born at 25 through 28 weeks. Although overall survival increased for infants aged 23 and 24 weeks, few infants younger than 25 weeks' gestational age survived without major neonatal morbidity, underscoring the continued need for interventions to improve outcomes for the most immature infants," the authors write.

Use of antenatal corticosteroids, an intervention recommended for improved neonatal outcomes, increased from 1993 to 2012 (24 percent to 87 percent), as did cesarean delivery (44 percent to 64 percent). Strategies to reduce lung injury, including less aggressive ventilation, are recommended. Delivery room intubation decreased from 80 percent in 1993 to 65 percent in 2012. Although most infants were ventilated, continuous positive airway pressure without ventilation increased from 7 percent in 2002 to 11 percent in 2012.

Despite no improvement from 1993 to 2004, rates of late-onset sepsis declined between 2005 and 2012 for infants of each gestational age. Rates of other complications declined, but bronchopulmonary dysplasia (a chronic lung disease developed after oxygen inhalation therapy or mechanical ventilation) increased between 2009 and 2012 for infants at 26 to 27 weeks' gestation.

"The study provides a global overview and level of detail not presented in earlier studies. Findings demonstrate that progress is being made and outcomes of the most immature infants are improving," the authors write. "These findings are valuable in counseling families and developing novel interventions."

"Although survival of extremely preterm infants has increased over the past 2 decades, including survival without major morbidity, the individual and societal burden of preterm birth remains substantial, with approximately 450,000 neonates born prematurely in the United States each year. To truly affect newborn outcomes, a comprehensive and sustained effort to reduce the high rates of preterm birth is necessary."

Editorial: Progress in the Care of Extremely Preterm Infants

Roger F. Soll, M.D., of the University of Vermont College of Medicine, Burlington, comments on this study in an accompanying editorial.

"There is no obvious breakthrough therapy emerging in the coming years. Perhaps cellular therapy, such as mesenchymal stem cells, will be an important advance in the care of these fragile infants. However, it is more likely that incremental change, such as applying quality improvement practices to outcomes other than nosocomial infection, will lead to improved outcomes."

"Stoll and colleagues have charted the progress made over the last 2 decades. It is clear that there are still a substantial number of extremely preterm infants who either die or survive after experiencing 1 or more major neonatal morbidities known to be associated with both short- and long-term adverse consequences. Although the neonatal-perinatal medicine community can be proud of the progress made, an additional commitment must be made to further improvements in the decades to come."