RESUMEN
The incidence of developmental delay and early intervention (EI) service utilization is not well documented among unauthorized Mexican immigrants, a vulnerable population. Individual interviews were conducted in Spanish with Mexican born women receiving maternal health care. Children 12-60 months of age were screened for developmental delay using the Ages and Stages Questionnaire. 12 % (n = 8) of children assessed (n = 65) were at risk for developmental delay. Of those at risk 38 % (n = 3) participated in EI. An additional 26 % of the children (n = 17) qualified for further monitoring, and of those 59 % (n = 10) received EI. Women with low health literacy had more than four times the odds of having a child with risk of developmental delay (aOR 4.4; 95 % CI 1.3-15.4). Developmental delay was associated with low maternal health literacy in unauthorized Mexican immigrants; however, rates of self-reported EI use in this population are higher than those seen nationally.