(353) An increased multidimensional early pregnancy allostatic load is associated with placentally-mediated adverse outcomes

Allostatic load (AL) is a multidimensional construct encompassing cumulative physiologic, psychological, and environmental stressors. An increased AL is associated with HTN and cardiovascular disease outside of pregnancy. However, it is unclear if AL is also associated with elevated CV complications in pregnancy.


Study Design:

Secondary analysis of a prospective cohort enriched for those at high a priori risk of PTB. Participants identifying as Black, White, and/or Hispanic, with singleton, non-anomalous gestations were recruited < 22 weeks, 2017-2022. At enrollment, baseline demographic and health information were collected and participants provided a blood sample via standard venipuncture. We considered 6 markers previously considered in other AL indices: CV domain factors (initial prenatal systolic BP, initial prenatal diastolic BP), a metabolic factor (pre-pregnancy BMI), and inflammation (plasma IL-6, IL-10, and IL-1β levels). Each marker was classified as ‘high’ (≥75^th centile; 1 point) or ‘low’ (< 75^th centile; 0 points). The total AL score was calculated by summing these 6 factors for a max AL score = 6. The primary outcome was a diagnosis of plac-comps (hypertensive disorders of pregnancy, birthweight < 10% for gestational age and sex, ± placental abruption).


Results:

493 participants were included; 113 (23%) had plac-comps. Baseline / pregnancy characteristics are shown in the Table. The ≥ 75^th centile used to classify each AL marker as ‘high’ and add +1 point to an individual’s AL score were: (1) SBP ≥125mmHg; (2) DBP ≥ 77 mmHg; (3) BMI ≥35.4 kg/m²; (4) IL-6 ≥11; (5)IL-10 ≥ 12; (6) IL-1β ≥13. The median AL score was 1 (IQR 0, 2); rates of plac-comps increased with higher AL scores (Figure 1a). In logistic regressions, an AL score of 0 was associated with a lower odds of plac-comps whereas AL scores ≥1 were associated with an increased adjusted odds (Figure 1b).


Conclusion:

A multidimensional AL score incorporating CV, metabolic health, and inflammatory biomarkers from early pregnancy is associated with the development of placentally-mediated adverse outcomes in a dose-dependent manner.