Acculturation and selected birth defects among non-Hispanic Blacks in a population-based case-control study

There are noted birth defects prevalence differences between race/ethnicity groups. For instance, non-Hispanic (NH) Black mothers are more likely to have an infant with encephalocele, although less likely to have an infant with anotia/microtia compared to NH Whites. When stratifying by nativity and years lived within the United States, additional variations become apparent.

Data from the National Birth Defects Prevention Study were used to calculate descriptive statistics and estimate crude/adjusted odds ratios (aORs) and 95% confidence intervals (95%CIs) among NH Blacks with one of 30 major defects and non-malformed controls. Total case/controls were as follows: U.S.- (2,773/1101); Foreign- (343/151); African-born (161/64). Study participants were also examined by number of years lived in the U.S. (≤5 vs. 6+ years).

Compared to U.S.-born, foreign-born NH Black controls tended to be older, had more years of education, and were more likely to have a higher household income. They also had fewer previous livebirths and were less likely to be obese. In the adjusted analyses, two defect groups were significantly attenuated: limb deficiencies, aORs/95%CIs = (0.44 [0.20-0.97]) and septal defects (0.69 [0.48-0.99]). After stratifying by years lived in the United States, the risk for hydrocephaly (2.43 [1.03-5.74]) became apparent among those having lived 6+ years in the United States. When restricting to African-born mothers, none of the findings were statistically significant.

Foreign-born NH Blacks were at a reduced risk for a few selected defects. Results were consistent after restricting to African-born mothers and did not change considerably when stratifying by years lived in the United States.