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

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

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.

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.

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.