Gestational age and adolescent mental health: evidence from Hong Kong's 'Children of 1997' birth cohort

Background Preterm, and more recently early term, birth has been identified as a risk factor for poor health. Whether the sequelae of late preterm or early term birth extends to poor mental health and well-being in adolescence is unclear and has not been systematically assessed. Method Linear regression was used to assess the adjusted associations of gestational age (very/moderate preterm (<34 weeks, n=85), late preterm (34-36 weeks, n=305), early term (37-38 weeks, n=2228), full term (39-40 weeks, n=4018), late term (41 weeks, n=809), post-term (>= 42 weeks, n=213)) with self-reported self-esteem at similar to 11 years (n=6935), parent-reported Rutter score assessing the common emotional and behavioural problems at similar to 7 years (n=6292) and similar to 11 years (n=5596) and self-reported depressive symptoms at similar to 13 years (n=5795) in a population-representative Hong Kong Chinese birth cohort 'Children of 1997' where gestational age has little social patterning. Results Very/moderate preterm birth was associated with higher Rutter subscore for hyperactivity (beta coefficients 0.5, 95% CI 0.01 to 1.00) at similar to 7 years but not at similar to 11 years, adjusted for sex, age, socioeconomic position, parents' age at birth, birth order and secondhand smoke exposure. Similarly adjusted, late preterm, early term, late term and post-term birth were not associated with self-esteem or depressive symptoms. Conclusions In a population-representative birth cohort from a non-Western-developed setting, gestational age had few associations with mental health and well-being in adolescence, whereas very preterm birth was specifically associated with hyperactivity in childhood. Inconsistencies with studies from Western settings suggest setting specific unmeasured confounding may underlie any observed associations.