Congenital Vascular Anomalies: Prenatal Diagnosis, Perinatal Outcome and Postnatal Follow up.

The aims of this study were to evaluate positive predictive value (PPV) of prenatal diagnosis in congenital vascular anomalies (CVAs) and to conduct postnatal follow-up. We reviewed suspected cases of CVAs with confirmed outcomes from 2008 to 2024. We documented the ultrasound (US) characteristics of CVAs as well as magnetic resonance imaging (MRI) findings and genetic tests. Thirty-four fetuses with suspected CVAs were included, with confirmed diagnosis in 30 cases (PPV: 88.2%). Fetal MRI demonstrated complete diagnostic concordance with US, including misdiagnosed cases. PIK3CA variants were absent in amniotic fluid, even in cases that subsequently tested positive on tissue biopsy. Among the 30 confirmed cases of CVAs, 24 (80%) were classified as vascular malformations, with 21 cases (87.5%) resulting in live births, of which 16 cases (76.2%) necessitated treatment. Six cases (20%) were vascular tumors, all resulting in live births, with two cases (33.3%) requiring treatment. Fetuses with anechoic low-flow vascularization masses on prenatal US had 2.7-fold higher need for postnatal intervention compared to fetuses with echogenic high-flow vascularization masses. The PPV of prenatal diagnosis in CVAs is high, with a limited contribution from MRI and genetic testing. Prenatal US characteristics are highly indicative of the nature of the lesion and the necessity for postnatal treatment.