479 - The association of maternal foreign-born status and education level on mortality of preterm infants among US Hispanic Subgroups

Poster Number: 479
Publication Number: 479.129

Kathleen E. Hannan, University of Colorado School of Medicine, DENVER, CO, United States; Stephanie L. Bourque, University of Colorado School of Medicine, Greenwood Village, CO, United States; Molly Passarella, Childrens Hospital of Philadelphia, Philadelphia, PA, United States; Scott A. Lorch, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States; Sunah S. Hwang, University of Colorado School of Medicine, Aurora, CO, United States

Background: In the US, significant racial and ethnic inequities in perinatal health outcomes exist. For the Hispanic birthing population, foreign-born women paradoxically have lower rates of low birthweight and preterm birth than US-born women, though this varies across Hispanic subgroups. Beyond the immediate birth period, data are lacking on whether these differences persist in preterm infant mortality rates (IMR). Further, little is known about the association of foreign-born status, specific Hispanic subgroup, and maternal education with preterm IMR.

Objective: Across US Hispanic subgroups, 1) evaluate the association of maternal foreign-born status and preterm IMR; 2) determine if the association of foreign-born status and IMR varies across education levels.

Design/Methods: Using linked national birth and death certificate data (2005-2014), we examined IMR among preterm infants ( < 37 wks gestation) of Hispanic mothers. Chi-square tests compared clinical/sociodemographic factors by Hispanic subgroup (Mexican, Puerto Rican, Cuban, Central/South American, other/unknown) and nativity (US vs foreign-born). We performed a multivariable logistic regression for associations between Hispanic subgroup, nativity, and IMR and a stratified analysis by Hispanic subgroup with an interaction term to determine if the association of foreign-born status and IMR varied across education levels

Results: Among 890,000 preterm Hispanic infants, the IMR was 29.6 per 1000 live births. This rate varied across subgroups and by nativity (Table 1). Adjusting for maternal/infant characteristics, infants of US and foreign-born Hispanic mothers had similar IMR (29.5 vs. 29.7, p=0.68). Maternal education of 0-8 years was associated with higher odds of IMR, while >12 years was associated with lower odds (Table 2). This effect was inconsistent across subgroups, with preterm infants of Cuban and Central/South American mothers not experiencing a protective effect with increased education, and only infants of US-born Puerto Rican mothers and of US-born mothers of other/unknown origin having lower odds with >16 years education.Conclusion(s): Maternal foreign-born status did not have a protective effective against IMR among preterm Hispanic infants. Both US and foreign-born Cuban and Central/South American mothers did not experience a protective effect of increased education against preterm IMR. These findings highlight the need to disaggregate the Hispanic birthing population into national origin groups to better understand particular factors associated with adverse perinatal outcomes for developing targeted interventions for specific populations.
Table 1. IMR (per 1000 live births) among live births of preterm infants to Hispanic women by Hispanic subgroup and nativity.*Adjusted for: Maternal age, maternal education, marital status, insurance status, maternal health conditions, gestational age, infant sex, maternal smoking during pregnancy, singleton birth, state of birth, and year.
Table 2. Adjusted odds ratios (AOR) for preterm infant mortality in the first year of life stratified by Hispanic subgroup including interaction of nativity (US-born vs. Foreign-born) and education level.