乌鸦传媒

While survival rates among extremely preterm infants have continued to improve in recent years, some may still face adverse neurodevelopmental outcomes later in childhood, according to a prospective study.

From 2013 to 2018, 78.3% of infants born extremely preterm survived to discharge, up from 76% in 2008 to 2012, reported Edward Bell, MD, of the University of Iowa in Iowa City, and colleagues.

The most significant increases in survival were in infants born at the earliest gestational ages. Among live-born infants delivered at 22 weeks, the survival rate jumped from 6.6% in 2008-2012 to 10.9% in 2013-2018, while survival among those delivered at 23 weeks increased from 32.3% to 49.4%, respectively, the researchers wrote in .

"These are incremental, small steps, but they are moving in the right direction," Bell told 乌鸦传媒.

However, in infants who were born at less than 27 weeks' gestation, rehospitalization and neurodevelopmental impairment were common at 2 years of age, Bell's group said. Of 2,458 children evaluated at a 2-year follow-up visit, 49.9% had been rehospitalized, while 48.7% had no or mild neurodevelopmental impairment, 29.3% had moderate impairment, and 21.2% had severe impairment.

Additionally, 8.4% had moderate to severe cerebral palsy, 1.5% had bilateral blindness, 2.5% required hearing aids or cochlear implants, and 15.4% required mobility aids or other supportive devices.

Because approaches to care for infants born extremely preterm tend to vary, data are needed to shape future clinical decision making, said Mikael Norman, MD, PhD, of the Karolinska Institutet in Sweden, in an .

"Neonatal intensive care of extremely preterm infants is based primarily on experience rather than evidence," Norman wrote. "Interventions that minimize patient suffering and morbidities need to be developed and consistently provided to move beyond knowledge of proportions of survival and disabilities as the only indicators of quality of care."

For this study, Bell and colleagues obtained data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development . They included infants born at 22 to 28 weeks' gestation at 19 network centers from 2013 through 2018. For infants born up until 2016, the researchers also collected data on post-discharge outcomes at a 2-year follow-up visit.

Of the 10,877 infants included in the study, 49% were girls, 26.5% were multiples, 9.3% were small for gestational age, and 5.5% were born with major birth defects. About 65% of all babies were born via C-section, but this accounted for only 3.1% born at 22 weeks and 39.7% born at 23 weeks. Median maternal age was 29 years.

Only 36.5% of infants born at 22 weeks were actively treated, while 88.5% of those born at 23 weeks, 97.9% born at 24 weeks, and nearly all born at 25 to 28 weeks received active treatment.

Among babies who were actively treated, 30% born at 22 weeks' gestation and 55.8% born at 23 weeks' gestation survived to discharge.

Of those who survived more than 12 hours after birth, 84.3% received mechanical ventilation during hospitalization, and nearly 80% received surfactant. The median length of hospitalization for all surviving infants was 93 days.

In-hospital morbidities differed by gestational age, and were more likely among infants born earlier. Overall, 8.9% had necrotizing enterocolitis, 2.4% had early-onset infection, 19.9% had late-onset infection, 14.3% had severe intracranial hemorrhage, 12.8% had severe retinopathy of prematurity, and 8.0% had severe bronchopulmonary dysplasia.

Bell and colleagues noted that the Neonatal Research Network is hospital-based, rather than population-based, and may not be generalizable to the entire U.S. preterm population. Additionally, the 2-year follow-up window provides a limited outlook into the future, and further studies are needed to assess health outcomes among extremely preterm infants later in childhood.

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