Brief report: birth status, medical complications, and social environment: individual differences in development of preterm, very low birth weight infants.

OBJECTIVE To assess whether medical complications mediate the relationship between birth status (i.e., birth weight and gestational age) and developmental outcome of preterm, very low birth weight (VLBW) infants, as well as the role of the early social environment (maternal distress and social support) in infant development. METHOD Birth status and medical complication information was collected during the child's NICU stay. Maternal distress was assessed with the Beck Depression Inventory and the Parenting Stress Index at 4 months corrected infant age. Social support was measured with the Dunst Scales at 4 months corrected age. Child development measures were collected at 4 and 13 months corrected age (Bayley MDI and PDI), and at 36 months chronological age (PPVT-R and Achenbach CBCL). RESULTS Medical complications mediated the birth status-outcome relationship at 4 and 13 months, but not at 36 months. The 36-month outcomes were predicted by 4-month maternal distress and social support. CONCLUSIONS Prematurity and VLBW are indirectly related to early developmental outcome through their association with medical complications. However, by 36 months, developmental outcomes are more closely related to aspects of the early social environment than to early physiological factors.