For Whom and How Does Prenatal Care Help? "Normal" or "Compromised" Births

Fu Fang, University at Albany, State University of New York (SUNY)
Timothy B. Gage, University at Albany, State University of New York (SUNY)
Erin O'Neill, University at Albany, State University of New York (SUNY)
Howard Stratton, University at Albany, State University of New York (SUNY)

Covariate Density Defined mixture of logistic regressions (CDDmlr) is applied to examine the effects of prenatal care of infant mortality in a heterogeneous birth cohort. The data used are the 2001 US non-Hispanic European and African American cohorts by sex with prenatal care utilization defined by the Kessner Index. The size of the “compromised” subpopulation significantly increases by 1.6%-2.5% and 2.4%-5.1% and the mean birth weight of “normal” births significantly decreases by 45-70 and 104-129 grams for intermediate and inadequate care, respectively, compared to adequate care. Prenatal care affects the mortality of “normal” infants directly, indicated by a significant log odds ratio (0.47-1.27) with less care independent of birth weight. Its net effect on the mortality of the “compromised” subpopulation is generally insignificant. Overall, the “direct” effect dominates the observed changes of infant morality by prenatal care. Our results also suggest racial disparities in the benefits of prenatal care.