Prenatal Diagnosis, Associations and Outcome for Fetuses with Congenital Absence of the Pulmonary Valve Syndrome

Background: The aim of this study is to review the spectrum of the prenatally detected absent pulmonary valve syndrome and its outcome after diagnosis.

Methods: Clinical data and echocardiographic findings of 37 cases with a fetal diagnosis of absent pulmonary valve syndrome between 2008 and 2020 were analyzed in this retrospective multicenter study.

Results: Median gestational age at diagnosis was 25 weeks. Three subtypes of absent pulmonary valve syndrome were observed: (1) with tetralogy of Fallot (n = 30; 81.0%); (2) absent pulmonary valve syndrome with intact ventricular septum (n = 5; 13.5%); (3) with complete atrioventricular septal defect (n = 2; 5.4%). In contrast to 7/25 fetuses (28%) with tetralogy of Fallot-absent pulmonary valve syndrome who had a patent ductus arteriosus, all 5 fetuses with absent pulmonary valve syndrome-intact ventricular septum had a patent ductus arteriosus (P <.001). No significant difference was found between the z-scores of pulmonary artery branches in fetuses with or without patent ductus arteriosus (P >.05). The analysis did not reveal any correlation between gestational week and z-scores of pulmonary artery, pulmonary artery branches (right pulmonary artery, left pulmonary artery), and ratio of aorta/pulmonary artery ratio. The echocardiographic measurements of survivors did not differ significantly from non-survivors (P >.05). Extracardiac anomalies were observed in 8/37 fetuses (21.6%). The incidence of extracardiac anomaly was significantly higher in cases of tetralogy of Fallot-absent pulmonary valve syndrome (P <.05). Overall, 9 fetuses (24%) had genetic anomalies. All 6 fetuses (20%) with 22q11.2 microdeletion were within the tetralogy of Fallot-absent pulmonary valve syndrome group. Overall survival after initial diagnosis in the total cases was 36.6% (11/30), with 9 of 30 (30%) tetralogy of Fallot-absent pulmonary valve syndrome cases and 2 of 5 (40%) absent pulmonary valve syndrome-intact ventricular septum cases.

Conclusions: In this largest series of absent pulmonary valve syndrome, extracardiac,and chromosomal anomalies were found to be a common occurrence. The risk of 22q11.2 microdeletion was higher in tetralogy of Fallot cases at 40%. The sizes of the pulmonary artery and its branches and the aorta had no correlation of high mortality antenatally or after birth, which were 63.4% and 47.7%, respectively.