Rates of Sudden Unexpected Infant Death (SUID) and its Subcategories in the U.S.: The Effect of Maternal Race, Ethnicity and Nativity.

Abstract

Objective: This study aimed to estimate (1) rates of SUID and its subcategories among infants of U.S.-born and foreign-born women, and (2) the extent to which maternal race/ethnicity modifies the relationship between maternal nativity and SUID rates.

Methods: Stratified and adjusted (for traditional demographic, clinical, and behavioral risk factors) Poisson regression analyses were performed on the National Center for Health Statistics linked 2021-2022 live birth-infant death database. Rates of SUID and its subcategories-sudden infant death syndrome (SIDS), accidental suffocation or strangulation in bed (ASSB), and unknown causes-were calculated for infants of women in the four largest U.S. racial/ethnic groups.

Results: Infants of U.S.-born women (n = 5,600,507) had an over three-fold greater SUID rate than infants of foreign-born women (n = 1,594,547): 115.5/100,000 vs. 34.8/100,000, RR = 3.3 (3.0, 3.6). Strikingly, the nativity disparity existed among infants of Non-Hispanic Asian (n = 431,532), Non-Hispanic Black (n = 1,025,573), Hispanic (n = 1,820,734) and Non-Hispanic White (n = 3,722,820) women: RR = 2.4 (1.7, 3.5), 4.9 (4.0, 6.1), 2.3 (2.0, 2.6), and 3.2 (2.5, 4.1), respectively. Maternal nativity disparities in SUID persisted after adjustment, overall (adjRR = 2.5 (2.3, 2.8)) and within each racial/ethnic group. Non-Hispanic Black infants had the widest disparity (adjRR = 3.3 (2.7, 4.1)). Similar results were observed for SIDS, ASSB, and unknown causes.

Conclusions for practice: Infants of U.S.- vs. foreign-born women have higher rates of SUID and its subcategories independent of traditional risk factors. This nativity disparity is widest among Non-Hispanic Black women. These findings warrant further attention and research regarding differences in environment, infant sleep practices and SUID death investigation among foreign-born and U.S.-born women.