Mexican-Americans' use of prenatal care and its relationship to maternal risk factors and pregnancy outcome.

We evaluate the adequacy of prenatal care use and the association of use to a series of maternal risk factors and pregnancy outcomes, such as low birthweight, preterm delivery, and macrosomia in both Mexican-Americans and non-Hispanic whites in Arizona. The data came from all live-birth certificates from 1986 and 1987 for a total of 101,202 (26,826 Mexican-Americans). We evaluated the adequacy of prenatal care using a redesigned index that accounts for three factors: the month when prenatal care began, the number of prenatal care visits, and the duration of pregnancy. From this index we identified six prenatal care groups: intensive, adequate, intermediate, inadequate, no-care, and missing/unknown. Overall, we observed ethnic differences in patterns of prenatal care use, social profiles, and medical risk factors. Non-Hispanic whites, compared to Mexican-Americans, showed a greater risk for low birthweight and preterm delivery in those groups receiving poor prenatal care versus those who received adequate care. Within Mexican-Americans the risk of low birthweight was not the same for all subgroups. A higher overall prevalence of preterm delivery and macrosomia in comparison to low birthweight occurred in Mexican-Americans. We discuss the implications of the results for the identification, interpretation, evaluation, and public health significance of perinatal health problems of Mexican-Americans.