A new study by Duke Health, published in the New England Journal of Medicine, has found that babies born extremely prematurely are now more likely to survive into toddlerhood without signs of moderate or severe neurological problems than those born at the same prematurity a decade earlier. The change may be due to improvements in care in neonatal intensive care units.
Over 61,000 babies are born too early each year in the UK and, sadly, about 1,200 of those babies are lost due to prematurity. Many who do survive suffer conditions such as learning difficulties, blindness, hearing loss and cerebral palsy.
A healthy gestation usually lasts around 40 weeks, although babies born at 37 weeks and beyond are considered full term and can be delivered safely. The recent study by Duke Health, which analysed records from a National Institutes of Health research network, looked at babies who were born between 22 and 24 weeks’ gestation, making them extremely premature and on the ‘borderline of viability’. Over 4,000 premature babies were used in the study and were assessed both at birth and then again at age 18 – 22 months. The results were compared with babies who had been born at the same stage of gestation 10 years before.
Data reported over the last five years has suggested that babies born prematurely have greater survival rates than ever before. This new study found similar results: babies born between 2008 and 2011 had a survival rate of 36%, an improvement on the survival rate of 30% for babies born between 2000 and 2003.
Less has been known about the cognitive effects of such prematurity on those infants who do survive. The recent study had encouraging results: of those who survived, 20% of the babies born more recently had no neurological impairment, compared with 16% for those born a decade earlier. The study also found that fewer premature infants had sepsis. In general, boys had poorer outcomes than girls.
The study did not look into the longer term effects of prematurity. Those who survive and do not have significant impairment at around two years of age are still at greater risk of various health problems in later life.
The researchers at Duke Health attributed the positive changes to improvements on neonatal intensive care units. There has been greater focus on preventing infections in recent years, and as a result, infection rates in neonatal units have decreased over the past 20 years. The study also suggested that the greater encouragement and support provided so that babies are given their mother’s milk whilst in neonatal intensive care units has been beneficial. Finally, the increased use of steroids for mothers who are suspected to be at risk of going into labour prematurely is thought to have helped. These steroids assist lung development and so give infants a greater chance of survival once they have been born.
Camilla Wonnacott, an associate in Penningtons Manches’ clinical negligence team, said: “This is encouraging news for parents of premature little ones. However, while these statistics do show an improvement over time, it is clear that there is still work to be done. Sadly, many babies born at this early stage of pregnancy do not survive and those who do may face considerable challenges.”