Evaluation of the Missouri WIC program: prenatal components.

A study was performed to evaluate the prenatal components of the Missouri Special Supplemental Food Program for Women, Infants and Children (WIC) Program. The study used WIC prenatal participants delivering in 1980 and their offspring's birth/fetal death certificates. A 93% match rate was acquired with a final study population of 6,732. Three basic methods of overall analysis were used to acquire a comparison group: covariate analysis, standardization, and pair matching. A higher mean birth weight was noted for the WIC total and WIC non-white group when the method of analysis was covariate or standardization; the latter was statistically significant. In either instance, the amount of increase was small. A reduced low-birth-weight rate was noted for the WIC total and the WIC non-white group regardless of the method of analysis used; the differences were statistically significant for the standardization method. Duration in WIC had a positive influence on both mean birth weight and low birth weight, regardless of race. High-risk groups used for program participation also were analyzed. Overall, this study showed that WIC prenatal nutritional supplementation has a positive, though not conclusive, impact on reducing low birth weight and raising mean birth weight.