The changing association between prenatal participation in WIC and birth outcomes in New York City

We analyze the relationship between prenatal WIC participation and birth outcomes in New York City from 1988-2001. The analysis is unique for several reasons. First, we have over 800,000 births to women on Medicaid, the largest sample ever used to analyze prenatal participation in WIC. Second, we focus on measures of fetal growth distinct from preterm birth, since there is little clinical support for a link between nutritional supplementation and premature delivery. Third, we restrict the primary analysis to women on Medicaid who have no previous live births and who initiate prenatal care within the first four months of pregnancy. Our goal is to lessen heterogeneity between WIC and non-WIC participants by limiting the sample to highly motivated women who have no experience with WIC from a previous pregnancy. Fourth, we analyze a large sub-sample of twin deliveries. Multifetal pregnancies increase the risk of anemia and fetal growth retardation and thus may benefit more than singletons from nutritional supplementation. We find no relationship between prenatal WIC participation and measures of fetal growth among singletons. We find a modest pattern of association between WIC and fetal growth among U.S.-born Black twins. Our findings suggest that prenatal participation in WIC has had a minimal effect on adverse birth outcomes in New York City. © 2005 by the Association for Public Policy Analysis and Management

Reduced risk of low weight births among indigent women receiving care from nurse-midwives

STUDY OBJECTIVE—To examine the effect of a comprehensive prenatal and delivery programme administered by nurse-midwives on the risk of low weight births among indigent women.
STUDY DESIGN—Historical prospective study. Birth outcomes among the cohort were compared with all county births during the same period, adjusting for maternal age and race. Results are expressed as relative risks with 95% confidence intervals.
SETTING—An enhanced Medicaid funded pre-natal programme administered by nurse-midwives from 1992 to 1994 in Westchester County, New York.
PARTICIPANTS—Indigent mothers (n=1443), between the ages of 15 and 44, who were residents of Westchester County and indicated having Medicaid or no health care coverage.
RESULTS—There were 1474 live births among cohort mothers. Mean (SD) gestational age was 39.4 (1.9) weeks. Less than 6% of births occurred before 37 weeks gestation. The mean birth weight of cohort infants was 3365.6 (518.6) g. Only 4.1% of the cohort births were less than 2500 g. Compared with all county births, the cohort showed a 41% reduction in the risk of low weight births (RR(lbw)=0.59, 95%CI: 0.46 to 0.73, p<.001 ) and a 56% reduction when compared with county Medicaid births only (RR=0.44, 95%CI: 0.34 to 0.57,( )p<.005) adjusting for maternal age and race. Larger reductions were found for very low weight births.
CONCLUSIONS—Mothers need not be considered at high risk for adverse pregnancy outcomes based on their socioeconomic status alone. Moreover, a comprehensive prenatal programme administered by nurse-midwifes may promote a reduction in adverse pregnancy outcomes among indigent mothers.


Keywords: low birth weight; prenatal care; indigent mothers; nurse-midwif