Racial disparities in preterm births and fetal losses

Project Summary (30 lines) Preterm birth (<37 weeks of gestation) increases the risk infant death, hospitalization, developmental disorders, and low educational attainment. Although non-Hispanic (NH) Black mothers show an increased risk (vs. NH whites) of delivering preterm, NH Black infants historically show―at each gestational age before term―improved health and survival relative to NH white infants. The main explanation for this counterintuitive finding assumes greater selection against frail NH Black fetuses. According to the selection argument, excess fetal loss among frail NH Black gestations results in a hardier cohort of survivors to birth but who are delivered preterm. Prior work describing this racial survival advantage has three important limitations. First, it continues to infer the survival advantage from data now nearly two decades old. Second, it includes no test of the fetal selection argument. Third, it fails to utilize a structural racism framework to understand the potential causes of, and changes over time and place in, racial differences in fetal loss and infant survival. Rapid changes in neonatal technology suggest that decades-old estimates of the survival advantage may have, since 2000, diminished―or even transformed into a disparity. We will use the universe of live births, infant deaths, and fetal deaths among NH Blacks and NH whites in the US (~65 million records, 1995 to 2018) to rigorously examine race-specific trends in preterm birth and infant mortality rates. We will link these records longitudinally by conception cohort to achieve several research objectives. First, we will determine whether NH Blacks (vs. NH whites) born preterm show a survival advantage—or a disparity—in infant mortality in the US. Second, we will investigate how the NH Black / NH white difference in preterm birth rates and infant mortality rates has changed over time, in response to fluctuations in fetal death rates and exogenous changes in neonatal technology (e.g., use of antenatal steroids). Third, we will use a structural racism theoretical framework to examine the extent to which dynamic race-based spatial indicators of inequality (e.g., segregation, incarceration rates) affect patterns across place and time in NH Black (vs. NH white) fetal loss, selection in utero, and infant mortality among preterm births. Our work is significant because we focus on the entire spectrum of perinatal outcomes, including the often neglected but quite large racial disparity in fetal death. Results are expected to advance the knowledge base on NICHD's high-priority research area to better understand racial/ethnic differences in infant health. Our approach will also inform our understanding of the extent to which structural racism may have maintained―or exacerbated―perinatal health disparities. Lastly, our place-based analysis will identify regions with potentially large disparities in fetal loss and perinatal survival that may benefit from targeted healthcare and non-healthcare resources.