According to a significant new study, infants born between 32 and 38 weeks of gestation are more likely to suffer developmental issues such as language delay, cognitive impairment, ADHD, and cerebral palsy than children born full term.
While many of the increased risks are minor, given that approximately 7% of newborns in the UK are born moderately preterm each year, the authors of the National Institute of Health and Care Research (NIHR) sponsored study warn they could have serious effects at the national level. Researchers at the Universities of York, Leeds, and Leicester evaluated data from over 75 studies conducted around the world, including over eight million children.
The study found that children born preterm had a higher risk of most developmental problems than those born full-term. While the risks decreased with each week of gestation, there was still evidence of a slight increase in the chance of many developmental abnormalities such as cerebral palsy, developmental delay, and cognitive impairment, even when children were born “early term,” between 37 and 38 weeks.
It is important to remember that whilst our study shows an increase in risk for children born moderately early relative to their peers born at full term, many children will not experience any developmental problems.
Dr Katherine Pettinger
Language delay was one of the most prevalent problems, affecting 222 per 1000 children born between 32 and 36 weeks, versus 47 per 1000 full-term children. Many children experience low educational attainment throughout their primary school years, with 300 per 1000 children born significantly preterm compared to 160 per 1000 children at full term.
While the risk of cerebral palsy is very modest for all children, the study’s findings indicate that it is 14 times higher for infants delivered at 32 to 33 weeks gestation than for children born full term. The review also discovered that the difficulties faced by children born between 32 and 38 weeks extend throughout childhood, with indications of increased risk and prevalence of cognitive impairment and low educational success continuing into high school.
Lead author of the study, Dr. Katherine Pettinger from the Department of Health Sciences at the University of York, said: “It is important to remember that whilst our study shows an increase in risk for children born moderately early relative to their peers born at full term, many children will not experience any developmental problems.
“The reasons behind our findings are not yet clear, but babies born just a few weeks early have different brain maturation to full-term children, and it is possible that birth between 32 and 38 weeks’ gestation may disrupt the evolution of neural connections, potentially contributing to a developmental disorder.
“Many babies that are born moderately preterm are delivered early for very good reasons, for example when the mother has a health condition such as preeclampsia. However, understanding the long-term implications of birth before full-term may influence obstetric decision-making in some cases. It is also vital that all healthcare professionals, and particularly pediatricians, are well informed of the potential consequences of preterm birth so that they can give evidence-based information to families and so opportunities for early intervention are not missed. “
According to current National Institute for Health and Care Excellence (NICE) standards, children born before 30 weeks should be observed until the age of two.
The researchers do not propose that all children born between 32 and 38 weeks gestation have repeated regular health appointments because many will show no evidence of developmental abnormalities, putting a huge load on NHS facilities. However, the researchers advocate for increased communication among schools, parents, and health experts, as well as improved teacher support.
Dr. Pettinger went on to say, “The statistics show that the impacts of being born a few weeks early are still present at primary school age. As a result, it makes sense for teachers to be aware and trained on how to support pupils born preterm and early term. More research is needed to look at large-scale population studies to examine how incidences of developmental problems link to gestational age and whether the patterns we saw in the current study are reproduced. We also want to see if children are typically impacted by more than one disorder, as knowing which disorders are likely to co-occur will help us develop more targeted interventions for children.”
