Gestational age at term not linked to academic performance

Gestational age at term not linked to academic performance | Image Credit: © Rido - © Rido - stock.adobe.com.

According to a recent study published in JAMA Network Open, there is not an association between academic achievement and gestational age at birth among children born at term.

Preterm birth has been associated with worse developmental outcomes, but it is unclear how gestational age impacts outcomes for children born at term. Of children born at 37 to 41 weeks of gestation, 37 to 38 weeks is considered early term, 39 to 40 weeks full term, and 41 weeks late term. In general, worse neonatal outcomes are seen in those born early term.

Induction is not recommended at 37 to 38 weeks because of associated perinatal complications. However, it is unclear if earlier delivery is better for infants at 39 to 40 weeks of gestation. Investigators conducted a study to determine the association between gestational age of 37 to 41 weeks and academic achievement.

Patient characteristic data was collected from birth certificates of children born from 1989 to 2009 in Iowa, while outcome data was collected from student scores on standardized school tests from grade 2 to grade 11, available through the 2017 to 2018 school year. Data sources were matched using the child’s name and date of birth.

Participants were singleton births with a gestational age of 37 to 41 weeks with at least 1 match to a school test score record. There were 553,459 patients who met these criteria, 536,996 of which had at least 1 math score and 537,078 at least 1 reading score.

Children born at 40 weeks of gestation were separately compared with those born at 37 weeks, 38 weeks, 39 weeks, and 41 weeks. Gestational age was evaluated based on either the clinical estimate or obstetric estimate in birth certificates. Calendar estimate was used as a secondary measure, determined by delivery date minus last menstrual period before pregnancy date.

School tests were based on the Iowa Tests of Educational Development, Iowa Tests of Basic Skills, and Iowa Assessments. Math and reading tests were the focus of the study, with outcomes measured based on standardized test scores.

Of mothers, 38% had not performed a previous live birth, 76.4% were married, 95.8% were White, 11.5% had less than high school level education, and 18.2% smoked during pregnancy. The mean test scores were 62.4 national percentile rankings (NPRs) for math and 60.8 NPRs for reading.

Children born at 39 weeks of gestation had statistically insignificant scores compared to children born at 40 weeks of gestation with differences of −0.028 NPRs for math and 0.085 NPRs for reading. Scores for children born at 41 weeks of gestation also were not indicated to have higher scores compared to children born at 40 weeks of gestation.

A slight decrease in math and reading scores were seen in children born at 37 and 38 weeks of gestation compared to 40 weeks, at –0.59 NPRs and –0.44 NPRs respectively for math. Reading scores were −0.066 NPRs and −0.19 NPRs respectively.

Children born at 41 weeks of gestation had higher average grades 3, 5, and 6 math test scores and grade 3 readings scores than children born at 40 weeks. However, no other statistically significant differences based on grade level were observed, though differences often decreased at higher grades.

These results indicated no association between gestational age and academic performance for at term births. Investigators recommended these results be considered when weighing associations of cognitive development and delivery timing at birth.

Reference

Wehby GL. Association between gestational age and academic achievement of children born at term. JAMA Netw Open. 2023;6(7):e2326451. doi:10.1001/jamanetworkopen.2023.26451