Risk of developmental delay increases exponentially as gestational age of preterm infants decreases: a cohort study at age 4 years

AIM: The aim of the study was to assess the influence of decreasing gestational age on the risk of developmental delay in various domains at age 4 years among children born at a wide range of gestational ages. METHOD: In a community-based cohort, the parents of 1439 preterm-born children (24 0/7 to 35 6/7 wks) and 544 term-born children (38 0/7 to 41 6/7 wks') born in 2002 and 2003 completed the Ages and Stages Questionnaire (ASQ) when their child was 3 years 7 months to 4 years 1 month old. The prevalence rates of abnormal scores on the ASQ-total problems scale were compared in preterm and term-born children and the resulting odds ratios for gestational age groups were calculated and adjusted for social and biological covariates. RESULTS: The prevalence rates of abnormal scores on the ASQ-total problems scale increased with decreasing gestational age: from 4.2% among term-born children to 37.5% among children born at 24-25 weeks' gestation (p