Preterm Birth Among US and Foreign-Born Non-Hispanic Black Birthing Parents in Massachusetts: Variation by Nativity, Region, and Country of Origin.

introductionForeign-born non-Hispanic Black (NHB) birthing parents are less likely to have a preterm birth (PTB) than US-born NHBs. There is further variation by region and country of origin. We update previous studies by examining PTB rates by nativity, region and country of origin among NHBs in Massachusetts, a state with a heterogeneous population of foreign-born NHBs, including communities excluded from previous studies.

methodsUsing 2011-2015 natality data from the three largest metropolitan areas in Massachusetts, we documented associations between nativity, region, and 18 individual countries of origin and PTB, using multivariable logistic regression to adjust for individual-level risk factors.

resultsPTB was highest among US-born NHBs (9.4%) and lowest among those from Sub-Saharan Africa (SSA) (6.6%). Country-specific rates ranged from 4.0% among Angolans to 12.6% among those from Barbados and Trinidad and Tobago. While NHBs from SSA had significantly lower odds of PTB, risk among those from the Caribbean and Brazil was not different from US-born NHBs. The significantly lower risk among foreign-born NHBs and SSAs, in particular, remained robust in adjusted models. DISCUSSION: Individual-level factors do not explain observed variation among NHB birthing parents. Future research should investigate explanations for lower PTB risk among SSAs, and congruent risk among foreign-born Caribbeans, Brazilians and US-born NHBs. Exposure to racism, a known risk factor for PTB, likely contributes to these inequities in PTB and merits further exploration. Prenatal care providers should assess place of birth among foreign-born NHBs, as well as exposure to racial discrimination among all NLB birthing parents.