Rarely Encountered Umbilical Cord Pathologies (Literature Review)

This review systematizes current knowledge about umbilical cord abnormalities (UCAs) — a heterogeneous group of anomalies including length abnormalities, number of vessels, attachments, nodes, cysts, and vascular malformations. Based on the analysis of scientific literature (2000–2024), the epidemiological data are presented: UCAs occur in 15–35% of pregnancies, with single umbilical artery (SUA) — in 0.5–5%, velmen insertion — up to 50% in monochorionic twins, and true nodes — in 0.3–1.2%. The review details complications: fetal growth restriction (FGR), chronic and acute hypoxia, antenatal death, risks during childbirth (vascular rupture in vasa praevia, asphyxia). Particular attention is paid to early diagnostic methods: ultrasound with Doppler (blood flow assessment, EAP), color Doppler mapping (Velmen attachment), 3D/4D ultrasound in STIC mode (nodes, spatial anomalies), CTG monitoring. Differentiated management tactics are substantiated: from dynamic observation at low risk to planned cesarean section for vasa praevia or IUGR. It is emphasized that timely diagnostics and an individualized approach reduce perinatal mortality and improve outcomes.