Umbilical Cord Cysts from the Second Trimester of Pregnancy: Clinical Insights from 12 Cases of a 22-year Study in a Single Tertiary Center

This study aimed to explore the clinical characteristics of umbilical cord cysts (UCCs) detected from the second trimester onwards in a single tertiary center over a 22-year period. The subjects consisted of a total of 12 cases of UCCs among 11 pregnant women (10 singleton pregnancies and 1 twin pregnancy), diagnosed at ≥ 14 weeks of gestation, and managed at Kurume University Hospital from 2000 to 2021. The maternal backgrounds, characteristics of the cysts, including their location, numbers, sizes, associated fetal/neonatal findings, and outcomes, were analyzed retrospectively. The median maternal age was 28 years, with diagnosis at 18.5 gestational weeks. Cysts were found near the umbilical ring (8 cases), in a free loop (3 cases), and in both of these locations (1 case). Single cysts appeared in 8 cases, and multiple cysts in 4 cases, with the median diameter being 25.0 mm. Sizes varied by gestation, being larger near the umbilical ring without correlation to cyst number. Among the 9 cases with cysts located near the umbilical ring, 5 cases had fetal abnormalities, including trisomy 18 (2 cases), Beckwith-Wiedeman syndrome (1), and intrauterine fetal death (1). Urachal remnants were found in 4 cases and omphalomesenteric duct remnants in 1 case after birth. When UCC is observed, particularly a cyst located near the umbilical ring, comprehensive fetal ultrasound screening is necessary, and attention should be paid to fetal anomalies that may coexist. In cases where these are not identified prenatally, the presence of conditions such as urachal remnants needs to be considered.