Developmental delays in children born at 36 weeks or earlier not detected until preschool, study says

Developmental delays may not be evident early in life, but children born preterm may be affected by delays by the time they reach school age. Photo by PHOTOCREO Michal Bednarek/Shutterstock

ANN ARBOR, Mich., July 25 (UPI) — Babies born prematurely often have developmental delays that aren’t detected until preschool or kindergarten, according to a new study, suggesting more monitoring may be needed.

Researchers at the University of Michigan found developmental delays show up later for preterm babies than for those born full term based on math and reading scores in kindergarten and preschool.

Preterm infants — born at between 34 and 36 weeks of gestation, as opposed to between 39 and 41 weeks — have lower brain volume, less distinct patterns of neural connectivity and other structural differences in the brain.

Based on the new study, these subtle differences in brain development are difficult to detect and don’t become noticeable enough until later in life, researchers say.

“We found small but meaningful differences in developmental outcomes between late preterm infants and full term groups, which if applied to larger populations, may have potentially significant long term public health implications,” Dr. Prachi Shah, M.D., a developmental and behavioral pediatrician at the University of Michigan, said in a press release.

For the study, published in the journal Pediatrics, researchers analyzed data on 1,000 late preterm infants born between 34 and 36 weeks’ gestation, 1,800 early term infants born between 37 and 38 weeks’ gestation and 3,200 term infants born between 39 and 41 weeks’ gestation collected as part of the Early Childhood Longitudinal Study Birth Cohort.

At 9 nine months old, late preterm infants had less optimal development outcomes than those born early term or term, an association unseen at 24 months of age — but which reemerged around entrance to preschool.

Among infants in the study, those born late preterm had less optimal reading and math schools in preschool, as well as lower scores in kindergarten reading, compared to children born at term.

The researchers suggest doctors more closely monitor children, depending on when they were born, for developmental delays as children age in order to intervene and minimize their effects, though more research is needed to fully understand the manifestation of the delays.