At 14%, non-Hispanic Black infants have twice the rate of preterm birth as non-Hispanic White infants. Further, when comparing Black people who were not born in the US versus native-born Black Americans, the latter are more likely to experience preterm birth.
A new study, published in the Maternal and Child Health Journal, found preterm birth among Black Americans also varied by nativity, region, and country of origin. The study examined rates of preterm birth among non-Hispanic Black (NHB) people in Massachusetts, a state chosen for its heterogeneous foreign-born NHB residents.
“Having systemic data on experiences of discrimination and exposure to racism is the first step in understanding how much it accounts for inequities in maternal and infant health outcomes across race, ethnicity and other socially marginalized groups,” said Joanne Almeida, an associate professor at Simmons School of Social Work and a lead author of the study.
The study was led by the Boston University School of Public Health, and parsed natality data from 2011-2015 in the 3 largest Massachusetts cities. The investigators examined correlations between nativity, region, 18 different countries of origin, and preterm birth among 28290 US births among NHB people. Using multivariable logistic regression, the investigators adjusted for individual-level risk factors such as marriage status, education, smoking history, and access to prenatal care.
The investigators found that preterm birth was highest among US-born NHBs (9.4%), and lowest among foreign-born Black parents from Sub-Saharan Africa (6.6%). Split by country of origin, preterm birth rates ranged from 4.0% among Angolans to 12.6% among NHBs from Barbados, Trinidad, and Tobago. At 9.2%, Caribbean and Brazilian immigrants have a risk of preterm birth comparable to US-born Black parents. The investigators noted that the significantly lower risk among foreign-born and Sub-Saharan African non-Hispanic Black people remained robust, even after adjusting the results.
Overall, preterm birth was more likely among US-born Black birthing parents than foreign-born. These results refuted the “immigrant health advantage” theory, which suggests foreign-born immigrants have better birth outcomes than people born in the US. The investigators noted that US-born and foreign-born Black people have different experiences with racist discrimination, and specifically, US Black women report higher levels of racism than foreign-born Black women.
The variation in premature births among non-Hispanic Black people could not be attributed to individual-level factors. The investigators wrote, “Exposure to racism, a known risk factor for preterm birth, likely contributes to these inequities in preterm birth and merits further exploration.”
The investigators concluded, “failing to disaggregate by these factors can mask variation in social experiences, history, and health, and thus underestimate inequities in Black [preterm birth] rates.”