Hypercoiling and Single Umbilical Artery Associated With Fetal Placental Malperfusion and Growth Restriction: A Case Report.

Hypercoiling of the umbilical cord can lead to fetal growth restriction and stillbirth because the cord is vulnerable to blood flow disturbances caused by external forces. A single umbilical artery (SUA) is a relatively common abnormality; however, isolated SUA is associated with fetal growth restriction and stillbirth. We report a case of fetal growth restriction with both SUA and hypercoiling. A 27-year-old primigravida was evaluated at 37 weeks of gestation. Prenatal ultrasonography revealed a small-for-gestational-age fetus with a single umbilical artery and a hypercoiled umbilical cord. Continuous fetal monitoring was initiated upon admission. Cardiotocography demonstrated recurrent prolonged decelerations, necessitating an emergency cesarean section. Placental histopathology revealed fetal vascular malperfusion with hyalinized avascular villi and thrombotic occlusion of one umbilical artery, indicating disturbed fetoplacental circulation likely related to SUA and hypercoiling. The coexistence of hypercoiling and a single umbilical artery was associated with the risk of fetal vascular malperfusion and growth restriction. Careful antenatal surveillance and timely delivery are essential to prevent adverse perinatal outcomes in multiple umbilical cord anomalies.