(1034) Predictors of fetal growth in patients with maternal cardiovascular disease- cardiac medications are protective

Objective: Fetal growth restriction is a possible complication of maternal cardiovascular disease. It remains unclear what characteristics of a given cardiac condition confer risk: lesion, severity, or functional status. The role of cardiac medications in mediating risk is also poorly understood. We aim to assess the impact of maternal cardiac disease and use of cardiac medications on fetal growth.

Study Design: We conducted a retrospective cohort study of singleton gestations managed in a high volume Cardio-Obstetrics program from 2018-2022. Cardiovascular variables (primary lesion type, lesion severity [CARPREG II score], functional status [NYHA class], cardiac medications) and all 2nd and 3rd trimester Hadlock estimated fetal weights (EFW) along with their respective gestational ages at collection were reviewed for this cohort. Multivariate linear regression was used to model EFW, the primary outcome, as a function of lesion type, lesion severity, functional status, the use of any cardiac medication, and gestational age (GA). Interactions were stipulated between (GA), functional status, and lesion severity. Lesion type was modeled separately from severity due to concern for collinearity.

Results: We identified 250 pregnancies and 935 ultrasounds. There were significant main effects on EFW from GA (P< 0.01), CARPREG II score (P=0.02), and use of cardiac medications (P=.005). Interactional effects were significant for: 1) GA and CARPREG II score (P=.004), 2)  CARPREG II score and NYHA class (P=0.05), 3) GA, CARPREG II score, and NYHA class (P=0.02). Worse functional status and increasing lesion severity had a negative impact on fetal growth; taking cardiac medications (most commonly beta blockers) was protective (Fig 1).

Conclusion: Maternal functional status significantly impacts the influence of CARPREG II score on fetal growth. Importantly, use of cardiac medications is associated with more normal fetal growth. Cardiac medications used to optimize maternal functional status may improve both maternal and neonatal outcomes.