Prenatal suspicion and ultrasound diagnosis of umbilical artery thrombosis: A case report with targeted Doppler evaluation and timely delivery

Umbilical artery thrombosis (UAT) is a rare complication that is strongly associated with adverse neonatal outcomes, and the diagnosis and selection of an appropriate delivery time for good neonatal outcomes is challenging. Here, we present a case of prenatal suspicion and ultrasound diagnosis of UAT: a case report with targeted Doppler evaluation and timely delivery. A 35-year-old (gravida 6, para 1) with reduced fetal movement at 32 weeks gestation, Doppler ultrasound showed that for gestational age, the pulsatility index (PI), resistance index, and peak systolic velocity/end-diastolic velocity ratio of the umbilical artery (UA), PI of the left uterine artery, and PI of the middle cerebral artery were all <5th centile; the systolic/atrial wave ratio of the ductus venosus was 50th to 95th centile. Then the examination focused on the umbilical cord, excessive torsion of the umbilical cord and 2 hyperechoic lesions in 1 UA were observed. Only 1 UA was detected in the bladder section by color Doppler flow, whereas previous ultrasound screening results in the mid-trimester showed 2 umbilical arteries in the same section. Additionally, electronic heart rate monitoring revealed a noncontractile stimulation test abnormality. UAT with fetal and hemodynamic changes were observed. Urgent cesarean section was performed 2 days later after comprehensive prenatal counseling. The infant was born alive at 1740 g, and Apgar scores were 9-10-10 in 1-5-10 minutes respectively. Postoperative recovery of the pregnant woman was unremarkable. Targeted Doppler evaluation and timely delivery are helpful for the diagnosis of UAT and obtaining a fine pregnancy result.