More Extremely Preterm Babies Survive - and Thrive
Babies born at just 22 to 24 weeks of pregnancy continue to have sobering outlooks—only about 1 in 3 survive. But according to a new study, those rates are showing small but measurable improvement. Compared to extremely preterm babies born a decade earlier, the study found a larger percentage are developing into toddlers without signs of moderate or severe cognitive and motor delay.
Changes to prenatal care, including greater use of steroids in mothers at risk for preterm birth, could have contributed to increased survival and fewer signs of developmental delay in these infants, the authors said.
“The findings are encouraging,” said lead author Dr Noelle Younge, a neonatologist and assistant professor of paediatrics at Duke University. “We see evidence of improvement over time. But we do need to keep an eye on the overall numbers, as a large percentage of infants born at this stage still do not survive. Those who survive without significant impairment at about age 2 are still at risk for numerous other challenges to their overall health.”
The researchers analyzed the records of 4,274 infants born between the 22nd and 24th week of pregnancy, far earlier than the 37 to 40 weeks of a full-term pregnancy. The babies were hospitalised at 11 academic medical centres in the Neonatal Research Network, part of the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health.
About 30 per cent of infants born at the beginning of the study (between 2000 and 2003), survived. That proportion increased to 36 per cent for babies born toward the end of the study (from 2008 to 2011), with the best outcomes for children born at 23 and 24 weeks. Overall survival for babies born at 22 weeks remained the same throughout the study, at just 4 per cent.
Over the 12-year study period, the proportion of infants who survived but were found to have cognitive and motor impairment at 18 to 22 months stayed about the same (about 14 to 16 per cent). But the proportion of babies who survived without evidence of moderate or severe neurological impairment improved from 16 per cent to 20 per cent.
“The culture of neonatal intensive care units has really changed in the past decade,” said senior author Prof C Michael Cotten, a neonatologist and professor of paediatrics at Duke. “We’ve taken a big focus on preventing infections, and there’s a lot more encouragement and support for the use of mother’s milk than there was 15 years ago, which has also been linked to better outcomes.”
Extremely preterm infants are highly susceptible to infections. Neonatal intensive care units have reported steady decreases in infection rates among extremely preterm infants over the past two decades.
“This is important because infections have been associated with greater risk of neurologic problems,” Cotten said.
Science Daily. February 16. New England Journal of Medicine. February 16.