Allostatic Load, Neighborhood Disadvantage, and Birth Outcomes

OBJECTIVES: We examined if the Index of Concentration at the Extremes, a measure of neighborhood disadvantage, was associated with preterm birth (PTB) and assessed mediation by allostatic load (AL). METHODS: We examined a subset of the Michigan Archive for Research on Child Health, a prospective ongoing cohort that began in 2016, with select biomarkers and prenatal records. We operationalized AL from the sum of eight parameters drawn from inflammatory biomarkers and prenatal records, which we dichotomized as ≥ 4 (High) or < 4 (Low). We tested for mediation of AL using Generalized Estimating Equations models clustered by zip code. RESULTS: Of the n = 392, 46% were Black, 16% of which delivered preterm. Black pregnant people had 1.21 times higher PTB odds if they lived in a more privileged county compared to those who did not (OR = 1.21, 95% CI = 0.54, 2.73) while non-Blacks had 36% lower odds (OR = 0.64, 95% CI = 0.22, 1.85), but neither were statistically significant. Living in a more privileged county was significantly associated with 70% lower odds of high AL (OR = 0.30, 95% CI = 0.13, 0.68). Both groups had higher although not statistically significant odds of PTB if they had high AL scores (Black: OR = 1.22, 95% CI = 0.42, 3.57; Non-Black: OR = 3.24, 95% CI = 0.32, 33.11). CONCLUSION: Although we observed trends in neighborhood disadvantage on PTB, the effects were not significant. Black pregnant people had a higher AL, but there was no evidence that AL mediated the association.