Adolescent Reproductive Health Outcomes Among Mexican-Origin Women on Both Sides of the U.S.-Mexico Border.

Much reproductive health research on the Latina population overlooks heterogeneity by national origin, nativity, and age and also ignores how U.S.-based populations differ from those in "sending" nations. The purpose of this study is to describe a history of adolescent birth, age at first sex, and contraceptive use at first sex in the Mexican-origin population in both the United States and Mexico. We developed a binational dataset merging two comparable nationally representative cross-sectional surveys in the United States and Mexico and used covariate balancing propensity scores to balance the age structure of our four samples: U.S.-born Latinas of Mexican origin, foreign-born Latinas of Mexican origin, U.S.-born non-Latina Whites, and Mexican women residing in Mexico. We used a negative binomial regression and calculated the predicted probability of experiencing at least one adolescent birth for each ethnicity/nativity group, stratified by 5-year age group. We also described age and contraceptive use at first sex. Foreign-born Latinas of Mexican origin and Mexicans in Mexico had similar adjusted probabilities of reporting an adolescent birth (30.1% and 29.9%, respectively), which were higher than those of Mexican-Americans (26.2%) and U.S.-born non-Latina Whites (11.6%). History of an adolescent birth is declining across all four groups among younger ages. Differences do not appear to be driven by the timing of first sex but by contraceptive use, which is increasing among younger age groups. Access to and use of effective contraception rather than timing of initiation of sexual activity is a key determinant of U.S. Latina and Mexican adolescent births. [ABSTRACT FROM AUTHOR]