Abstract P246: Association Between Life’s Essential 8 Cardiovascular Health Scores During Pregnancy and Vascular Integrity in the Placenta

Abstract

Background: Adverse pregnancy outcomes (APOs) identify pregnant people at increased risk of later cardiovascular disease. Poor antenatal cardiovascular health (CVH) quantified using components of the Life’s Simple 7 ideal CVH framework has been associated with higher APO incidence, indicating modifiable aspects of CVH during pregnancy may be related to pregnancy health. Placental pathology is also common in APOs, but it is unclear if antenatal CVH is directly related to placental health. Further, clinically-used dichotomous measures of placental pathology limit investigation of associations. Thus, the aim of this study was to examine the relationship between antenatal CVH and a novel, continuous marker of placental vascularization. Hypothesis: We hypothesized higher (healthier) antenatal CVH scores would be associated with higher (healthier) vascularization in the placenta. Methods: Participants enrolled in the Magee Obstetric Maternal & Infant Biobank and one of two prospective observational cohort studies examining activity patterns in pregnancy (MoM Health or Pregnancy 24/7). Antenatal CVH was quantified with a pregnancy-adapted Life’s Essential 8 framework assessed during each trimester and averaged across gestation. Components included sleep, diet, smoking, objective physical activity, pre-pregnancy BMI, blood pressure, 50g glucose challenge test results, and gestational weight gain. Component scores were averaged for a composite score (possible range, 0-100; higher indicated better CVH). Immunohistochemistry of placenta tissue was performed. Sections were stained with CD34 antibody to highlight vascular endothelial cells and counterstained with hematoxylin. Whole-slide images were digitized. Software computed the number of pixels positive for CD34 (numerator) and the total pixels (denominator); the ratio was the outcome of fetal vascular percentage (FV%), or the proportion of villous tissue occupied by fetal vessels. Linear regression associated CVH scores with FV%. Results: Placenta tissue was obtained from 64 participants (mean±SD age = 32±4.9 years). CVH score averaged across gestation was 72.6±10.7 points and decreased significantly from the first to third trimester (72.8±12.7 vs. 65.1±11.9, p<0.01). FV% was 26.3±5.13 percentage points. Associations between CVH scores and FV% approached but did not reach significance (p<0.2) in each trimester and across gestation. A 10-point increase in CVH averaged across gestation was non-significantly associated with a 0.82 percentage point increase in FV% (p=0.18). Post-hoc power analysis of this novel metric identified sufficient power to detect a 1.5 percentage point change in FV% per 10-point change in CVH score. Conclusion: Antenatal CVH was not significantly associated with placental vasculature, though a small sample size limits conclusions. Replication in a fully-powered sample is warranted.