Prenatal ultrasound analysis of single umbilical artery and combined malformations

Objective: To analyze the incidence of single umbilical artery (SUA) diagnosed by prenatal ultrasound and the types of combined fetal structural malformations. Methods: A retrospective analysis was performed on 141 577 singleton pregnancies who underwent continuous prenatal ultrasonography in Children’s Hospital of Soochow University from January 1, 2013 to January 31, 2022. Based on postpartum umbilical cord data or pathological examination，the incidence of SUA in singleton pregnancies was calculated and the combined malformations were analyzed. Results: The incidence of SUA was 0.55% (778/141 577) in singleton pregnancy, with isolated single umbilical artery (iSUA) accounting for 60.93% (474/778) and non-isolated single umbilical artery (niSUA) accounting for 39.07% (304/778). The absence rate of the left and right umbilical arteries was 51.7% (402/778) and 48.3% (376/778), respectively. The SUA with absence of right umbilical artery had a higher incidence of malformation comorbidities than those with absen