Agenesis of the Ductus Venosus and Its Association With Genetic Abnormalities.

Objective: To investigate the association of agenesis of the ductus venosus (ADV) with genetic abnormalities using genetic studies-Chromosomal Microarray Analysis (CMA) and Exome Sequencing (ES).

Design: Retrospective study of all fetuses diagnosed with ADV between January 2013 and December 2022 in a tertiary center.

Results: ADV was diagnosed in 33 fetuses. The diagnosis was made at a mean gestational age of 21.2 ± 8.4 weeks. Conventional karyotype was applied in a single fetus (3.0%), CMA was applied in 21 fetuses (66.7%), and five fetuses (22.8%) were additionally tested with ES. ADV was isolated in eight fetuses (24%), whereas in 25 (76%) it was associated with abnormal ultrasound findings, including increased nuchal translucency (NT), intrauterine growth restriction (IUGR) and variable structural malformations, mostly cardiac (42%) followed by central nervous system (CNS) and skeletal malformations (24%). Genetic abnormalities were found in six fetuses out of 22 investigated (27%), of which 3 were detected by ES, 3 by CMA and 1 by conventional karyotype. A higher incidence of genetic aberrations was evident among ADVs associated with abnormal ultrasound findings. Genetic abnormalities were indicative of Prader Willi/Angelman syndrome, Noonan syndrome, CASK related disorder, 16q24.3 microdeletion syndrome and Trisomy 21.

Conclusion: ADV associated with abnormal ultrasound findings is commonly correlated with genetic abnormalities and consequently unfavorable pregnancy outcomes. Our study emphasizes the value of genetic studies chiefly among cases associated with abnormal ultrasound findings, enabling early diagnosis of fetal pathologies associated with ADV, and providing better parental counseling.