231 - DETERMINING ANTENATAL RISK FACTORS FOR PROGRESSION AND OUTCOME OF ATRIOVENTRICULAR VALVE REGURGITATION IN PATIENTS WITH ATRIOVENTRICULAR SEPTAL DEFECT

Background:

Background: Atrioventricular valve regurgitation (AVVR) affects morbidity and mortality in patients with atrioventricular septal defects (AVSD). There is limited literature on the frequency and progression of AVVR through gestation. Our aim was to review the incidence of fetal AVVR, the progression in fetal life as well as in the perinatal transition and whether fetal AVVR was associated with adverse outcomes.

METHODS AND RESULTS:

Methods: A single center retrospective review of fetuses with the diagnosis of AVSD born between 2007-2023 was performed. Medical records and fetal echocardiograms (echo) were reviewed. AVVR was categorized as none, mild, moderate or severe on colour Doppler. Hemodynamically significant AVVR progression was defined as those from none or mild to > moderate or moderate to severe. AVVR severity was compared from the first to last fetal echo and the last fetal to the first postnatal echo.

Results: Of 211 with AVSD, 129 had fetal echo and outcome data for review and were included in the analyses, with 75 terminations of pregnancy and 7 lost to follow up not included. Of the 129, 56(43%) had unbalanced AVSD and 73(57%) balanced AVSD and 42(33%) had heterotaxy (Table). Mean gestational age at first fetal echo was 24 (12-33) weeks and at last 35 (19-39) weeks. Of the 129, 120 (93%) had none-mild AVVR at initial study, 6 (5%) moderate and 3 (2%) severe AVVR. Most (93/101, 92%) with AVVR demonstrated no significant change in AVVR severity through gestation. Eight (8%) had significant progression of AVVR severity with 5 progressing from none-mild to > moderate AVVR and 3 from moderate to severe. AVVR severity and progression was not associated with ventricular imbalance, heterotaxy or genetic diagnosis. AVVR severity at last fetal echo correlated well with initial postnatal echo in the majority (99/105, 94%). There were 5 who had no AVVR antenatally that had > moderate AVVR after birth. Moderate-severe AVVR was associated with worse outcome (p = 0.002). Of the 6 fetuses with severe AVVR antenatally, 2 suffered an intrauterine fetal demise, 3 early postnatal deaths ( < 1 month) and only 1 survived post neonatal heart transplant.


Conclusion:

Conclusion: The majority of fetuses with AVSD demonstrated no significant AVVR or AVVR development/progression through gestation and in the perinatal transition. AVVR severity and progression in fetal AVSD does not correlate with ventricular imbalance, heterotaxy or genetic diagnosis. Severe AVVR is associated with poor fetal and neonatal outcomes.