Gestational age at term affects academics

Gestational age independently predicts academic achievement, even among full-term infants (born at 37 to 41 weeks), according to a new study. Two extra weeks of gestation can have a significant effect on later test scores, the results suggest.

Researchers compared birth records and scores on standardized third-grade reading and math tests for 128,050 singleton children born between 37 and 41 weeks' gestation to women living in New York City. Test scores were significantly lower among children born at 37 and 38 weeks than for children born at 39, 40, or 41 weeks, after adjusting for birth weight and a number of economic, social, and obstetric variables. Reading and math scores showed increased benefit with each additional week of gestation from 37 to 41 weeks.

Children born at 41 weeks scored 1 point higher on reading and math tests than children born at 37 weeks-the equivalent of a 1.5-point difference on an IQ test. Children born at 37 weeks had a 33% higher risk of severe reading problems in third grade than children born at 41 weeks and a 19% greater chance of at least moderate problems in math.

The researchers also urge taking into account the link between gestational age at term and later academic performance when considering elective early deliveries for nonmedical reasons, a growing trend.

Noble KG, Fifer WP, Rauh VA. Nomura Y, Andrews HF. Academic achievement varies with gestational age among children born at term. Pediatrics. 2012. Epub ahead of print.