Multiple factors as mediators of the reduced incidence of low birth weight in an urban clinic population

A five year prospective observational study was initiated in 1985 at Howard University to describe the nutritional, clinical, dietary, lifestyle, environmental, and socioeconomic characteristics of women who enrolled in the hospital prenatal clinic. The participants were nulliparous, between the ages of 18 and 35 years, free of diabetes and abnormal hemoglobins (sickle cell disease, thalassemia, and hemoglobin C), and had been admitted prior to the 29th week of gestation. During the three year period from 1985-1988, the incidence of low birth weight (LBW) in 239 deliveries to project participants was 8.3%, whereas that of women simultaneously enrolled in the prenatal clinic with the same eligibility requirements, but not recruited for the research project, was 21.9% (P = 0.001). The incidence of LBW in infants of African American women with these eligibility requirements who were delivered by private physicians but were not enrolled in the project, was 6.3% The reduction in LBW of infants delivered to participants in this study is attributed to the enhanced social and psychological support by project staff during their pregnancies. The caring, sensitive demeanor of the research project staff may have empowered the participants to (a) give greater compliance (91 vs. 70%) in the ingestion of the routine physician-prescribed vitamin/mineral supplement, which provided nutrients low (less than 70% of the 1989 RDAs) in their customary diets, such as folate, pyridoxine, iron, zinc, and magnesium and (b) show greater accountability in keeping prenatal clinic appointments. It is hypothesized that the enhanced social support resulted in stress reduction and stimulation of immunocompetence in these low income women.