Early childhood trajectories of domain-specific developmental delay and gestational age at birth: An analysis of the All Our Families cohort

OBJECTIVE: To describe developmental domain-specific trajectories from ages 1 through 5 years and to estimate the association of trajectory group membership with gestational age for children born between ≥34 and <41 weeks gestation. METHODS: Using data from the All Our Families cohort, trajectories of the domain-specific Ages & Stages Questionnaire scores were identified and described using group-based trajectory modeling for children born ≥34 and <41 weeks of gestation (n = 2664). The trajectory groups association with gestational age was estimated using multinomial logistic regression. RESULTS: Across the five domains, 4-5 trajectory groups were identified, and most children experienced changing levels of risk for delay over time. Decreasing gestational age increases the Relative risk of delays in fine motor (emerging high risk: 1.46, 95% CI: 1.19-1.80; resolving moderate risk: 1.11, 95% CI: 1.03-1.21) and gross motor (resolving high risk: 1.21, 95% CI: 1.04-1.42; and consistent high risk: 1.64, 95% CI: 1.20-2.24) and problem solving (consistent high risk: 1.58 (1.09-2.28) trajectory groups compared to the consistent low risk trajectory groups. CONCLUSION: This study highlights the importance of longitudinal analysis in understanding developmental processes; most children experienced changing levels of risk of domain-specific delay over time instead of having a consistent low risk pattern. Gestational age had differential effects on the individual developmental domains after adjustment for social, demographic and health factors, indicating a potential role of these factors on trajectory group membership.