290: Association between acculturation and preterm birth is not mediated by measures of social stress


      Acculturation, a process of changing cultural norms due to acclimation to new or different cultural settings, has been associated with preterm birth (PTB) in the US. We sought to evaluate whether this association may be mediated by social support, resilience, or perceived racism.

      Study Design

      Secondary analysis of a prospective cohort study of nulliparous women recruited from 8 sites across the US. Degree of acculturation was defined using birthplace and self-rated English competency (see Table 1). Low social support, low partner support, and low resilience were defined as scores in the lowest quartile of the Multidimensional Scale of Perceived Social Support (MSPSS), MSPSS partner support subscale, and Connor-Davidson Resilience scale, respectively. High perceived racism was defined as 3 or more discrimination experiences on the Krieger Racism scale. All women in the cohort were included unless information to determine acculturation was lacking. Univariable analyses assessed the relationship between acculturation and each potential mediator. Next, mediation analyses were conducted via paramed (STATA 14), comparing counterfactual logistic regressions of PTB on strong acculturation and each mediator. The indirect or mediation effect is the change in PTB resulting from changing the value of the mediator (social stressor) while holding acculturation constant. Adjusted direct and indirect effect odds ratios (aORs) are reported (Figure 1).


      Of 9942 women eligible for analysis, 8102 (81.5%) were strongly acculturated and 1840 (18.5%) were moderately/weakly acculturated. In univariate analyses, moderately/weakly acculturated women reported lower partner support, lower resilience, and higher perceived racism (Table 1). Mediation analyses revealed no effect of these stressors on the relationship between acculturation and PTB, as indicated by non-significant aORs for indirect effects (Figure 1, red circles). Direct effect aORs for strong acculturation remained significant (Figure 1, blue squares), demonstrating an independent association of strong acculturation with PTB.


      In this group of nulliparous women, higher social stress is more common for weakly/moderately acculturated women. However, the relationship between strong acculturation and increased PTB is not mediated by social stressors. Additional study is needed to identify the mechanisms of this relationship.
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