METHODS: We included nulliparous individuals with singleton pregnancies who self-identified as Hispanic, non-Hispanic Black (NHB), or non-Hispanic White (NHW) and participated in the nuMoM2b cohort study (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be). First-trimester CVH was quantified using 6 routinely assessed factors in pregnancy included in the American Heart Association Life's Essential 8 score (0-100 points), in which higher scores indicate better CVH. Oaxaca-Blinder decomposition evaluated the extent to which racial and ethnic differences in CVH were explained by differences in individual- and neighborhood-level factors (age, socioeconomic characteristics, psychosocial factors, nativity, perceived racial discrimination, and area deprivation index).

RESULTS: Among 9104 participants, the mean age was 26.8 years, 18.7% identified as Hispanic, 15.6% identified as NHB, and 65.8% identified as NHW. Mean (SD) CVH scores were 76.7 (14.1), 69.8 (15.1), and 79.9 (14.3) in the Hispanic, NHB, and NHW groups, respectively (P<0.01). The individual- and neighborhood-level factors evaluated explained all differences in CVH between Hispanic and NHW groups and 82% of differences between NHW and NHB groups. Racial and ethnic differences in educational attainment explained the greatest proportion of differences in CVH. If mean years of education among the Hispanic (14.0 [2.5]) and NHB (13.4 [2.4]) groups were the same as the NHW (15.8 [2.4]) group, mean CVH scores would be higher by 2.98 points (95% CI, 2.59-3.37) in the Hispanic and 4.28 points (95% CI, 3.77-4.80) in NHB groups.