Natural history of suspected developmental delay between 12 and 24 months of age in the 2004 Pelotas birth cohort

Aims: To describe the incidence and persistence of suspected developmental delay (SDD) between 12 and 24 months of age and associated factors in the 2004 Pelotas Birth Cohort. Methods: A cohort of 4262 newborns, 3907 of whose were monitored from 12 to 24 months of life. SDD was established by Battelle Screening Developmental Inventory. The adjusted analyses were carried out using Poisson regression. Relative risks and 95% confidence intervals were calculated. Results: Incidence of SDD between 12 and 24 months of age was 1.8% (95% CI: 1.4–2.3). After the adjusted analyses, the following factors increased the risk of the incidence: Apgar 5′ < 7, preterm delivery, low socio‐economic level, intergestational interval ≤24 months, not having been told stories in the previous 2 weeks, lack of children's books at home and male gender. A total of 390 children were positive in the 12 month (prevalence of 10%; 95% CI: 9.0–10.9). From these children, 58 remained positive up to 2 years of age, with a persistence rate of 15.6% (95% CI: 11.9–19.3). The following were factors for persistence in SDD: Apgar 5′ < 7, low socio‐economic level, intergestational interval ≤24 months, breastfeeding duration <6 months and not having been told stories in the previous 2 weeks. Conclusions: Easy access to children's literature and telling stories to children are inexpensive measures that may have an impact on the child's development between 12 and 24 months of life.