Homicide in Pregnant and Postpartum versus Nonpregnant and Nonpostpartum Populations: Re-estimation of a Rate Ratio using a Person-time Framework

Abstract We aim to re-estimate the national homicide rate ratio between nonpregnant/nonpostpartum and pregnant/postpartum women accounting for person-time exposure, which prior studies overlooked. Using a theoretical framework for descriptive epidemiology, we complete a retrospective analysis to estimate the pregnancy-associated homicide rate and re-estimate the national homicide rate ratio between pregnant/postpartum and nonpregnant/nonpostpartum populations in 2020. We use National Vital Statistics System death, fetal death, birth, and Census Bureau data to identify the population at risk. We compare mortality rates and 95% confidence intervals overall and stratified by race, ethnicity, and age. Among the 9,905,908 pregnancies contributing person-time, there were 185 homicides. The relative homicide risk was 35% higher among nonpregnant/nonpostpartum compared to pregnant/postpartum populations. Pregnancy was only associated with elevated risk among ages 10-19 (homicide rate ratio 3.82; 95% CI 2.39-5.77). Homicide rate ratios between nonpregnant/nonpostpartum and pregnant/postpartum women calculated accounting for exposure time and pregnancy transitions contradict previous estimates. Accurate assessment of mortality rates is essential to develop strategies protective against maternal mortality.