Contribution of previable live births to disparity in infant mortality of US-born Puerto Ricans compared with infants of other Hispanic origins

Objectives: Although US-born Hispanics experience infant mortality rates (IMRs) which are lower than the national rate, within the Hispanic population, infants of Puerto Rican origin experience higher IMRs than other Hispanics. We aimed to describe the contribution of deaths among previable live-born infants to disparity in IMRs comparing Puerto Rican infants to infants of other Hispanic origins. Study design: Retrospective, descriptive analysis. Methods: We analyzed data from the Centers for Disease Control and Prevention (CDC) WONDER online database representing linked US live births and infant deaths from 2005 to 2014. Data were stratified by race and ethnicity as well as by Puerto Rican and non–Puerto Rican Hispanic origin. Live births <23 weeks of gestation were classified as previable. Ten-year IMRs were calculated as the number of deaths divided by the number of live births for each group over the entire decade. Results: Puerto Rican IMR of 7.34 (per 1000 live births) was higher than the US rate of 6.34 as well as the non–Puerto Rican Hispanic IMR of 5.15. Approximately 22% of US deaths were attributable to previable live births compared with 27% among Puerto Ricans and 20% among non–Puerto Rican Hispanics. The contribution to IMR of previable births among Puerto Ricans measuring 1.96 per 1000 total live births was 42% higher than the US rate of 1.38 and 90% higher than the non–Puerto Rican Hispanic rate of 1.03. Conclusions: Further research is needed to develop interventions to reduce disparity in previable birth rates, particularly among infants of Puerto Rican origin.