Birth at 39 weeks gestation does not affect numeracy and literacy outcomes at school age: JAMA

In the Australian statewide, population-based study, the researchers used a causal inference framework based on target trial emulation to link perinatal data on births between 2005 and 2011 to educational outcomes at 7 to 9 years of age. The study population included 155,575 children. Of these children, 49 456 (31.8%; 50.5% were boys) were born at 39 weeks gestation and were compared with 106 119 (68.2%; 49.1% boys) born at 40 to 42 weeks gestation.

Literacy and numeracy outcomes were assessed at age 7 to 9 years using Australian National Assessment Program–Literacy and Numeracy data and defined by overall z score across five domains (reading, grammar and punctuation, spelling, writing, and numeracy). Population average causal effects were estimated using multiple imputations and doubly robust inverse probability weighted regression adjustment.

The researchers reported the following findings:

• Birth at 39 weeks gestation was not associated with altered educational outcomes for children aged 7 to 9 years compared with their peers born at 40 to 42 weeks gestation (mean [SE] z score, 0.0008 vs –0.0031).
• Each educational domain was investigated, and no significant difference was found in grammar and punctuation (risk difference [RD], −0.006), spelling (RD, 0.001), numeracy (RD, −0.009), reading (RD, −0.008), or writing (RD, 0.006) scores for children born at 39 weeks gestation compared with those born at 40 to 42 weeks gestation.
• Birth at 39 weeks gestation also did not increase the risk of scoring below national minimum standards in any of the 5 tested domains.

"These findings provide reassurance to clinicians and families that planned birth at 39 weeks gestation was not associated with advanced primary school-aged educational achievement," the researchers concluded.