biostudies-literatureLueth AJNICHD NIH HHSNCATS NIH HHSNHLBI NIH HHS974-982https://www.ebi.ac.uk/biostudies/studies/S-EPMC9712159biostudies-literatureUnknown140(6)<h4>Objective</h4>To assess the association between allostatic load, as an estimate of chronic stress, and adverse pregnancy outcomes.<h4>Methods</h4>This was a secondary analysis of nuMoM2b (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be), a prospective observational cohort study. Our primary exposure was dichotomous high allostatic load in the first trimester, defined as 4 or more of 12 biomarkers in the "worst" quartile. The primary outcome was a composite adverse pregnancy outcome: hypertensive disorders of pregnancy (HDP), preterm birth, small for gestational age (SGA), and stillbirth. Secondary outcomes included components of the composite. Multivariable logistic regression was used to test the association between high allostatic load and adverse pregnancy outcomes, adjusted for potential confounders. Mediation and moderation analyses were conducted to assess the role of allostatic load along the causal pathway between racial disparities and adverse pregnancy outcomes.<h4>Results</h4>Among 4,266 individuals, 34.7% had a high allostatic load. Composite adverse pregnancy outcome occurred in 1,171 (27.5%): 14.0% HDP, 8.6% preterm birth (48.0% spontaneous and 52.2% indicated), 11.0% SGA, and 0.3% stillbirth. After adjustment for maternal age, gravidity, smoking, bleeding in the first trimester, and health insurance, high allostatic load was significantly associated with a composite adverse pregnancy outcome (adjusted odds ratio [aOR] 1.5, 95% CI 1.3, 1.7) and HDP (aOR 2.5, 95% CI 2.0-2.9), but not preterm birth or SGA. High allostatic load partially mediated the association between self-reported race and adverse pregnancy outcomes. The association between allostatic load and HDP differed by self-reported race, but not for a composite adverse pregnancy outcome, preterm birth, or SGA.<h4>Conclusion</h4>High allostatic load in the first trimester is associated with adverse pregnancy outcomes, particularly HDP. Allostatic load was a partial mediator between race and adverse pregnancy outcomes. The association between allostatic load and HDP differed by self-reported race.Obstetrics and gynecologyAllostatic Load and Adverse Pregnancy Outcomes.PMC9712159U10 HL120018U10 HL120019UL1 TR000153U10 HD063053U10 HD063020U10 HD063041U10 HD063037U10 HL119993U10 HD063048U10 HD063036U10 HD063047U10 HL119991U10 HD063046U10 HL119992U10 HL119990U10 HL120034U10 HD063072UL1 TR001108U10 HL120006U10 HL119989Blue NMJohnson JMurtaugh MAllshouse AALevine LDSilver RMLueth AJKim JKGrobman WAWilson FASimhan HNNational Institutes of Health (NIH), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b), and National Heart, Lung, and Blood Institute (NHLBI) nuMoM2b Heart Health Study (nuMoM2b-HHS)falseAllostatic Load and Adverse Pregnancy Outcomes.<h4>Objective</h4>To assess the association between allostatic load, as an estimate of chronic stress, and adverse pregnancy outcomes.<h4>Methods</h4>This was a secondary analysis of nuMoM2b (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be), a prospective observational cohort study. Our primary exposure was dichotomous high allostatic load in the first trimester, defined as 4 or more of 12 biomarkers in the "worst" quartile. The primary outcome was a composite adverse pregnancy outcome: hypertensive disorders of pregnancy (HDP), preterm birth, small for gestational age (SGA), and stillbirth. Secondary outcomes included components of the composite. Multivariable logistic regression was used to test the association between high allostatic load and adverse pregnancy outcomes, adjusted for potential confounders. Mediation and moderation analyses were conducted to assess the role of allostatic load along the causal pathway between racial disparities and adverse pregnancy outcomes.<h4>Results</h4>Among 4,266 individuals, 34.7% had a high allostatic load. Composite adverse pregnancy outcome occurred in 1,171 (27.5%): 14.0% HDP, 8.6% preterm birth (48.0% spontaneous and 52.2% indicated), 11.0% SGA, and 0.3% stillbirth. After adjustment for maternal age, gravidity, smoking, bleeding in the first trimester, and health insurance, high allostatic load was significantly associated with a composite adverse pregnancy outcome (adjusted odds ratio [aOR] 1.5, 95% CI 1.3, 1.7) and HDP (aOR 2.5, 95% CI 2.0-2.9), but not preterm birth or SGA. High allostatic load partially mediated the association between self-reported race and adverse pregnancy outcomes. The association between allostatic load and HDP differed by self-reported race, but not for a composite adverse pregnancy outcome, preterm birth, or SGA.<h4>Conclusion</h4>High allostatic load in the first trimester is associated with adverse pregnancy outcomes, particularly HDP. Allostatic load was a partial mediator between race and adverse pregnancy outcomes. The association between allostatic load and HDP differed by self-reported race.2022-01-01T00:00:00Z2022 Dec2025-04-05T12:10:36.667Z2025-04-05T12:10:36.667ZS-EPMC97121593635795610.1097/AOG.000000000000497110.1097/aog.0000000000004971