Interpregnancy intervals and child development at age 5: A population data linkage study

Objective To investigate the associations between interpregnancy intervals (IPIs) and developmental vulnerability in children's first year of full-time school (age 5). Design Retrospective cohort study using logistic regression. ORs were estimated for associations with IPIs with adjustment for child, parent and community sociodemographic variables. Setting Western Australia (WA), 2002-2015. Participants 34 574 WA born singletons with a 2009, 2012 or 2015 Australian Early Development Census (AEDC) record. Main outcome measure The AEDC measures child development across five domains; Physical Health and Wellbeing, Social Competence, Emotional Maturity, Language and Cognitive Skills (school-based) and Communication Skills and General Knowledge. Children with scores 1.15). IPIs of 60-119 months and ≥120 months, were associated with an increased risk of developmental vulnerability on each of the five AEDC domains, with greater odds for each domain for the longer IPI category. Conclusions IPIs showed independent J-shaped relationships with developmental vulnerability, with short (