Accuracy and impact of prenatal diagnosis of common arterial trunk

Objectives: Outcome of common arterial trunk (CAT) depends mainly on truncal valve function, presence of coronary artery abnormalities and presence of interrupted aortic arch. The main objective of this study was to evaluate the accuracy of prenatal diagnosis of CAT by analyzing prenatal vs postnatal assessment of: (1) anatomic subtypes and (2) truncal valve function. The secondary objective was to assess the potential impact of prenatal diagnosis of CAT on postnatal mortality and morbidity by comparing prenatally vs postnatally diagnosed patients.

Methods: This was a retrospective analysis of all CAT patients diagnosed either prenatally, with postnatal or fetopsy confirmation, or postnatally, from 2011 to 2019 in a single tertiary center. Cohen's kappa statistic was used to evaluate agreement between pre- and postnatal assessment of anatomic subtypes according to Van Praagh and of truncal valve function. Mortality and morbidity variables were compared between prenatally vs postnatally diagnosed CAT patients.

Results: A total of 84 patients (62 liveborn with prenatal diagnosis, 16 liveborn with postnatal diagnosis and six terminations of pregnancy with fetopsy) met the inclusion criteria. The accuracy of prenatal diagnosis of CAT anatomic subtype was 80.3%, and prenatal and postnatal concordance for subtype diagnosis was only moderate (κ = 0.43), with no patient with CAT Type A3 (0/4) and only half of patients with CAT Type A4 (8/17) being diagnosed prenatally. Fetal evaluation of truncal valve function underestimated the presence (no agreement; κ = 0.09) and severity (slight agreement; κ = 0.19) of insufficiency. However, four of five cases of postnatally confirmed significant truncal valve stenosis were diagnosed prenatally, with fair agreement for both presence and severity of stenosis (κ = 0.38 and 0.24, respectively). Mortality was comparable in patients with and those without prenatal diagnosis (log-rank P = 0.87). CAT patients with fetal diagnosis underwent earlier intervention (P < 0.001), had shorter intubation time (P = 0.047) and shorter global hospital stay (P = 0.01).

Conclusions: The accuracy of prenatal diagnosis of CAT is insufficient to tailor neonatal management and to predict outcome. Fetal assessment of truncal valve dysfunction appears unreliable due to perinatal transition. Improvement is necessary in the fetal diagnosis of anatomic subtypes of CAT requiring postnatal prostaglandin infusion. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.