Background Post-term birth, defined as birth after pregnancy duration of 42 weeks, is associated with increased neonatal morbidity and mortality. The long-term consequences of post-term birth are unknown. We assessed the association of post-term birth with problem behaviour in early childhood. Methods The study was performed in a large population-based prospective cohort study in Rotterdam, The Netherlands. Pregnant mothers enrolled between 2001 and 2005. Of a cohort of 5145 children, 382 (7%) were born post-term, and 226 (4%) were born preterm. Parents completed a standardized and validated behavioural checklist (Child Behavior Checklist, CBCL/1.5–5) when their children were 1.5 and 3 years old. We examined the relation between gestational age (GA) at birth, based on early fetal ultrasound examination, and problem behaviour with regression analyses, adjusting for socio-economic and pregnancy-related confounders. Results A quadratic relationship between GA at birth and problem behaviour indicates that both preterm and post-term children have higher behavioural and emotional problem scores than the term born children. Compared with term born children, post-term born children had a higher risk for overall problem behaviour [odds ratio (OR) ¼ 2.10, 95% confidence interval (CI) ¼ 1.32–3.36] and were almost two and a half times as likely to have attention deficit / hyperactivity problem behaviour (OR ¼ 2.44, 95% CI ¼ 1.38–4.32). Conclusions Post-term birth was associated with more behavioural and emotional problems in early childhood, especially attention deficit / hyperactivity problem behaviour. When considering expectant management, this aspect of post-term pregnancy should be taken into account.

Post-term birth, preterm birth, behavioural and emotional problems, childhood,
International Journal of Epidemiology
Department of Psychology

El Marroun, H, Zeegers, M, Steegers, E.A.P, van der Ende, J, Schenk, J.J, Hofman, A, … Verhulst, F.C. (2012). Post-term birth and the risk fo behavioural and emotional problems in early childhood. International Journal of Epidemiology. doi:10.1093/ije/dys043.