摘要：Objectives . We examined trends and racial disparities (White, African American) in trimester of prenatal care initiation and adequacy of prenatal care utilization for US women and specific high-risk subgroups, e.g., unmarried, young, or less-educated mothers. Methods . Data from 1981–1998 US natality files on singleton live births to US resident mothers were examined. Results . Overall, early and adequate use of care improved for both racial groups, and racial disparities in prenatal care use have been markedly reduced, except for some young mothers. Conclusions . While improvements are evident, it is doubtful that the Healthy People 2000 objective for prenatal care will soon be attained for African Americans or Whites. Further efforts are needed to understand influences on and to address barriers to prenatal care. In 1985 the Institute of Medicine promoted the enrollment of all women into a system of prenatal care as a national policy initiative to improve birth outcomes in the United States. 1 To reach this goal by lessening the financial barriers to prenatal care, Congress enacted legislation in the mid- and late 1980s that incrementally expanded Medicaid eligibility to previously ineligible pregnant women. 2, 3 State-level evaluations of these policies revealed increases in Medicaid enrollment, accompanied by both earlier initiation and more adequate utilization of prenatal care. 4, 5 Similarly, national assessments of prenatal care use over the last 2 decades reveal ongoing improvements in the early entry and regular receipt of prenatal care. 6 Although short of the Healthy People 2000 and Healthy People 2010 objectives of 90% of US women initiating care in the first trimester, 7 this proportion increased to more than 83% in 1999. 8 Adequate use of prenatal care as measured by both the month that care began and the number of visits received (adjusted for gestational age at delivery) has also increased, while the percentage of women with no prenatal care or a late start of care has declined. 6, 9 In spite of the enthusiasm generated by these advancements in prenatal care use, concerns have been raised that not all racial, ethnic, and socioeconomic groups have equally realized these gains. Some writers have suggested that women at greatest risk of poor pregnancy outcomes had less improvement in their access to and use of prenatal care. 10 African American women and women with less education have been highlighted as specific groups for which trends toward more favorable prenatal care use have lagged, particularly for intensive utilization of care. 10 Further, one report has suggested that the discrepancy in late or no prenatal care use between Whites and African Americans has not changed over the last decade, a period when racial disparities in infant mortality continued to grow. 9 The objectives of this study are to (1) examine trends in early, adequate, and intensive use of prenatal care by African American and White women in the United States; (2) establish whether previously existing racial disparities in early and adequate use of prenatal care have been modified; and (3) determine whether improvement in intensive use of prenatal care has been racially disproportionate. In addition, for each racial group, we investigated the prenatal care trends of women with high-risk factors, e.g., young maternal age, low education, and single marital status. Regardless of ethnic or racial group, women with these maternal characteristics have been identified as having less adequate prenatal care use and are at greater risk of low birthweight, preterm delivery, and other poor pregnancy outcomes. 11, 12
