Despite innovative techniques to keep premature babies healthy, death rates and lingering health problems among extremely preterm babies remained unchanged for decades.
Premature births, occurring before 37 weeks, remain high in Europe and the U.S., where it affects one out of every eight babies. The risks of being born too early are also well documented, and include cognitive problems that can lead to lower math and reading scores in school, respiratory and immune system deficits that can put preemies at risk of asthma and other health conditions that are costly to treat, as well as early death. The health challenges and death rates for those born even earlier, before 26 weeks of pregnancy, are greater still, but researchers wanted to determine if newer interventions designed to improve the health of these extremely premature babies helped them to live longer and avoid more serious developmental and physical problems later in life.
Unfortunately, that’s not what they found. “We didn’t expect to see rates disappear,” says study author Neil Marlow, professor of neonatal science at the University College London Institute for Women’s Health. “We wanted to determine a more global picture of extreme preterm survival and later problems. Since 1995, we’ve done a lot of things that could change these outcomes…But things are relatively unchanged. There are improvements in survival and survival without disability, but rates and distributions of problems are similar.”
In two studies published online in the journal BMJ, scientists in the UK report that although preemie survival rates are up, the number of serious health issues and disabilities remain stubbornly unchanged between 1995 and 2006. In one study, there was no drop in the number of premature newborns leaving the hospital with serious health problems over that period, and in the second analysis, the rate of longer lasting major health and developmental problems among children born before 26 weeks also remained the same.
Both studies relied on data from two large studies, known as EPICure and EPICure2, that included all babies born in the UK before 26 weeks gestation in 1995 and in 2006. The first study compared survival rates and health issues such as lung, brain and eye problems recorded from birth until the babies were discharged from the hospital in each of the two years; changes in these rates might reflect advances in the way premature babies are treated in the hours and days after being born.
Indeed, the study authors reported a 13% improvement in survival rates in the first week after birth between 1995 and 2006, but the rates of babies who continued to experience serious health problems, like lung, brain and eye issues before they were discharged remained the same. More concerning is the fact that the researchers found a 44% increase in in neonatal intensive care (NICU) admissions, which means that although more babies are being admitted, likely due to complications from being born too soon, the care they receive doesn’t seem to be translating into fewer health problems. “That’s quite a staggering, huge increase,” says Marlow of the rise in NICU admissions. “We are not entirely sure why that is, and need to follow-up, but we know that the things we are doing are promoting early survival, but beyond the first week, deaths were unchanged.”
The authors believe that although more medical interventions were available in 2006 compared to 1995, such as better treatments to promote lung maturation and decreased used of steroids that have been linked to cerebral palsy, being born premature carries with it more serious consequences of incomplete development that cause major health problems that early interventions may not be able to address.
While the first study focused on the health outcomes during the first weeks of preemies’ lives, the second investigation followed up with preterm babies when they were three years old, and compared health outcomes of those kids born between 22 weeks and 25 weeks in 1995 to those born before 27 weeks in 2006. Overall, there was an 11% improvement in the proportion of children surviving to three years without a disability, from 23% in 1995 to 34% in 2006. The disabilities the researchers measured, which included cognitive problems, motor deficits, sensory and communication impairments as well as cerebral palsy, were greatest among those born earliest, and declined with longer pregnancies. But about 45% of those born at 23 weeks still had moderate to severe disabilities and other health problems, with the most severe deficits in learning. “As these kids go through childhood, their learning problems and behaviors during school are going to be their greatest problems,” says Marlow.
That doesn’t mean that most preemies are destined to experience developmental and health problems are they get older. The results should be interpreted cautiously, the authors say, since they were unable to follow-up with every child, and the children should be monitored over longer periods in order to fully understand the scope and severity of early birth on development. “Only assessment of the 2006 cohort at school age will clarify whether there have been important changes in the high prevalence of impaired cognitive and behavioral outcomes,” they write.
Some critics argue that the data from 1995 is no longer relevant, given how differently babies born preterm are treated today. But, if that’s the case, says Marlow, then he and his colleagues should have seen greater improvements in health outcomes among the babies born in 2006. “We have to think hard about the care we provide,” he says. “In fact, we think these findings imply that [the data from 1995] are very relevant, and help us understand what’s happening and why some of the same problems continue to exist. These kids are going to require a lot of health care and support as they go through childhood. We need to understand how we can help this problem by nurturing brain growth in the nursery and clinically.” Only with improved interventions for babies born extremely preterm can they start to shake off the health legacy of being born too soon.