Babies born too late or too early were found to underperform their term counterparts. Photo by Christianbella/GoodFreePhotos

WASHINGTON, Nov. 8 (UPI) -- Being born too early or too late may have long-lasting implications for a child's academic performance, researchers suggest.

In a study published in the International Journal of Epidemiology, scientists examined the relationship between cognitive development and premature birth. The study's authors concluded poor birth conditions have a negative impact on neurodevelopment.


"Less favorable outcomes of post-term infants with poor fetal growth suggest that placental insufficiency may become particularly toxic to neurodevelopment the longer a pregnancy endures," lead author Hein Heuvelman said in a press release.

During the study, researchers examined data from over 2 million live births in Sweden between 1973 and 1994. They obtained academic information by using the National School Register from Statistics Sweden. Academic performance was measured using the final grade completed on secondary education.

Grades were found to be lower for pre-term and post-term populations than their control group counterparts. Grades for extremely pre-term births were lower by 0.43 standard deviations, while extremely post-term grades were lower by 0.15 standard deviations.

Scientists say their study marks the first project to detail the relationship between pregnancy duration and academic performance across the full range of pregnancy. Despite their findings, they concede there may be shared familial traits which also influence early or late births. Other potential factors include poor maternal diet, smoking during pregnancy, and maternal obesity.