The influence of proximity of prenatal services on small-for-gestational-age birth.

Some studies suggest that prenatal services may decrease the risk of poor fetal growth for full-term infants, but have not examined the influence of the availability of community health and social services. The availability of prenatal services may have a stronger effect among women already at high risk of a small-for-gestational-age (SGA) birth. Singleton full-term (> or = 37 weeks gestation) California births for 1997-98 (n = 744,736) were geocoded to maternal Census tract of residence. Women were placed into one of three demographic risk groups utilizing combinations of maternal age, marital status, parity, and education. SGA was defined as birthweight less than the 10th percentile for gestational age. Locations of WIC sites, prenatal care providers, and perinatal outreach programs were geocoded. Multilevel logistic regression was used to model the influence of community health care services on SGA, adjusting for additional maternal and community factors. There was no association between SGA and community services available for either high- or low-risk women, in either unadjusted or adjusted models. The addition of maternal prenatal care utilization to models did not change the results. Maternal residence near prenatal services was not associated with SGA, regardless of demographic risk; other community factors may warrant consideration.