Grade 7 school performance of children born preterm: a retrospective Canadian Cohort study

Importance Data on the middle school outcomes of preterm children are limited and have methodologic issues. Objective To study the association between preterm birth and grade 7 school performance. Methods A retrospective population-based cohort study of children born in Manitoba, Canada between 1994 and 2006 using their grade 7 school performance data. A secondary sibling cohort was created comprising children born preterm and their full-term siblings. Primary exposure was preterm birth categorized as <28, 28–33 and 34–36 weeks gestation. The two co-primary grade 7 outcome measures were: not meeting the mathematics competencies, and not meeting the student engagement competencies. Multivariable logistic regression models tested the association between preterm birth and both co-primary outcomes; adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. Results 7653 preterm (gestational age median [IQR]: 35 weeks [34,36]) and 110,313 term (40 [39,40]) were included. 43% of < 28 weeks, 18% of 28–33 weeks and 17% of 34–36 weeks had the mathematics co-primary outcome compared to 13% of term children. The corresponding % for the student engagement outcome were 42%, 24%, 24% and 24% respectively. Preterm birth was associated with the mathematics (<28 weeks: 5.48, 3.89–7.70; 28–33 weeks: 1.47, 1.27–1.70; 34–36 weeks: 1.26, 1.16–1.35) and student engagement outcomes (<28 weeks: 2.49, 1.76–3.51; 28–33 weeks: 1.21, 1.06–1.39; 34–36 weeks: 1.09, 1.01–1.16). However, there was no difference in outcomes among the sibling cohort. Conclusions and relevance Children born preterm had lower grade 7 performance compared to children born term in this population-based cohort. Screening and supports for them in their middle school years are warranted.