Research Suggests Babies Born Before 39 Weeks Have A Higher Risk For ADHD

It's well known that babies born prematurely are more at risk for health concerns, but what about babies born just a little bit early who are still considered full term? That's what researchers at Rutgers University explored in a new study, published in The Journal of Pediatrics, with a focus on the risk for attention deficit hyperactivity disorder (ADHD).

When a baby is born before 37 weeks gestation, it's considered a premature birth (via Stanford Medicine Children's Health). Prematurity can be due to stress, infection, being pregnant with multiple babies, or uterine bleeding. While the rate of premature birth in the U.S. grew from 1990 to 2006, it has since been decreasing.

Research shows that babies born prematurely are not only at risk for intellectual and developmental disabilities but are also linked to long-term health conditions. Some of these include cerebral palsy, neurological disorders, mental health conditions, and ADHD (via March of Dimes). In this new study, researchers wanted to know how ADHD affected babies born at term, between 37 and 41 weeks of pregnancy (via U.S. News & World Report).

The study, published in The Journal of Pediatrics, found that those born at 37 to 38 weeks gestation were more likely to experience ADHD than those born between 39 and 41 weeks (via U.S. News & World Report). Researchers looked at data from the nationwide Fragile Families and Child Wellbeing study, which sampled approximately 1,400 births in nonmarital families in 75 hospitals across the country between 1998 and 2000. The children's mothers were interviewed over the next nine years, and the children's teachers provided evaluations of the children at nine years old.

Researchers re-evaluated this data in their new study. They found that kids who were born between 37 and 38 weeks of pregnancy scored notably higher for hyperactivity, ADHD, and inattention. Compared to babies born after 39 weeks, those born before 39 weeks had 23% higher scores for hyperactivity and 17% higher scores for ADHD. For each week of gestational age, there was a 6% lower hyperactivity score and a 5% lower score for ADHD and inattention.

Researchers highlighted the importance of these findings as evidence for regular ADHD screenings for children born between 37 and 38 weeks gestation. They also pointed to the importance of delaying elective births until after 39 weeks. This adds to a growing body of research suggesting that elective deliveries should not be performed before 39 weeks — babies go through significant development of the lung, liver, and brain between 37 and 39 weeks (via American Academy of Pediatrics).