Sports participation and preterm birth: a nationwide birth cohort in Japan.

backgroundChildren born preterm may be less physically active than children born term because of neurocognitive problems, reduced lung function, and poor physical fitness. We evaluated sports participation of children and adolescents who had been born preterm (<37 weeks) and early term (37-38 weeks) in 2001.

methodsData from a nationwide longitudinal survey (n = 47,015, including 2375 children born preterm) were analyzed. As indicators of sports participation, we used responses to questions about participation in sports clubs at 7 and 10 years old and in extracurricular school sports at 15 years old.

resultsChildren born very preterm (25-31 weeks) and moderately to late preterm (32-36 weeks) were less likely to participate in sports clubs at 7, 10, and 15 years old than children born full term (39-41 weeks). Compared with children born full term, the adjusted risk ratios for participation in extracurricular school sports at 15 years old were 0.86 (95% confidence interval: 0.75-0.98) for children born very preterm, 0.92 (0.88-0.97) for children born moderately to late preterm, and 1.00 (0.98-1.02) for children born early term.

conclusionsOur findings suggest that preterm birth is associated with less participation in organized sports during childhood and adolescence than full-term birth. IMPACT: Research investigating associations between preterm birth and physical activity among children born in the 2000s is limited. This study shows that preterm birth was associated with less participation in organized sports during childhood and adolescence than full-term birth, especially in boys, and the participation in organized sports of children born preterm decreased as gestation shortened. During childhood, boys born early term were also less likely to participate in organized sports than boys born full term, suggesting a continuum with preterm births. These findings offer important additional insights into the limited evidence available for predicting future health outcomes for preterm infants.