Developmental tempo in children aged 0-5 years living under unfavourable environmental conditions

To describe the dynamics of development along the early years of life among children living under unfavorable socioeconomic conditions.

In 5401 children younger than 6 years old living in Florencio Varela and in the Matanza-Riachuelo River Basin (Matanza, Villa 21-24, Wilde, Villa Inflamable and Acuba), areas with a high proportion of families with unmet basic needs, a logistic regression analysis was used to estimate the median age at attainment of 13 psychomotor developmental milestones; differences between these ages and median age at attainment of milestones as per the national reference were plotted on the y-axis, while the median age as per the national reference was plotted on the x-axis.

Three stages were observed: the first one between 0 and 270 days with normal development, in which the median age at attainment was similar to that of the national reference; a second one of progressive development delay; and a third one of recovery at 1260 days. Adjusted linear spline slopes were 0.06 (not significant), -0.26 (p < 0.0001) and 0.26 (p < 0.01) for stages 1, 2 and 3, respectively. The three slopes were statistically different from each other. The stage of normal development (stage 1) was attributed to the protective effect of the mother and the family environment; stage 2 of progressive delay, to the unfavorable impact of the environment, and stage 3 of partial recovery was attributed to attending a daycare center. These findings allow the implementation of effective interventions at each stage.

Three periods with different developmental tempos were identified.