More very premature babies are surviving and with fewer neurological impairments
Changes in ICU culture are key
By Dave Andrusko
The study appeared today in the New England Journal of Medicine and its bland headline conceals very, very encouraging results: “Survival and Neurodevelopmental Outcomes among Periviable Infants.”
But the conclusion of the study, led by Duke Health, is nicely captured in a story written by Samiha Khanna of the Duke Department of Pediatrics: “More extremely preterm babies survive, live without neurological impairment.”
This is not, by any means, to minimize the challenges faced by babies born between 22 and 24 weeks of pregnancy, nor to ignore that the survival rates are even better for babies born at 23 and 24 weeks. But it is to acknowledge that there has been a major uptick in survival rates between the early 2000s and 2011.
According to the NEJM, the records of 4,274 infants born between the 22nd and 24th week of pregnancy and hospitalized at 11 academic medical centers, were analyzed “across three consecutive birth-year epochs”– 2000–2003 ; 2004–2007 ; and 2008–2011.”
Khanna explains that the team, lead by Noelle Younge, M.D., a neonatologist and assistant professor of pediatrics at Duke, found there had been a 6% increase in survival rates, between the first and the third “epochs”:
About 30 percent of infants born at the beginning of the study (between 2000 and 2003), survived. That proportion increased to 36 percent 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 percent.
What about “cognitive and motor impairment”?
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 percent). But the proportion of babies who survived without evidence of moderate or severe neurological impairment improved from 16 percent to 20 percent.
“Researchers in the Neonatal Research Network reported in 2015 that survival was increasing in this vulnerable population,” Dr. Younge told Khanna . “One concern was that the improved survival might have been accompanied by a greater number of infants who went on to have impairments in the long term, such as cerebral palsy, developmental delay, hearing and vision loss. However, we actually are seeing a slight improvement.”
The obvious question is why? A number of possible factors were cited. Very premature babies, as you would expect, are very prone to infections. Over the past 20 years, the infection rate has gone steadily down, according to the study published in NEJM. The likelihood of neurological problems goes up when the baby contracts an infection.
Fortunately, “The culture of neonatal intensive care units has really changed in the past decade,” senior author C. Michael Cotten, M.D., a neonatologist and professor of pediatrics at Duke, told Khanna. “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.”
Other factors cited included an increased use of steroids in expectant mothers . This can assist the baby’s lungs to mature prior to birth.
“At the beginning of the study, 58 percent of the expectant mothers had received steroids to boost fetal development,” Khanna reported. “That figure increased to 64 percent by the end of the study.”
Dr. Cotton acknowledged, of course, that there is “a long way to go” to improve survival rates and reduce ensuing medical problems.
But he concluded, “We’re always looking at how we can make further headway and continue to improve survival and reduce illness in this population.”