To explore the feasibility of prenatal ultrasound in the diagnosis of single umbilical artery (SUA) in early pregnancy and its relationship with fetal chromosome abnormality.

The general information, ultrasonic characteristics, chromosome karyotype or microarray analysis results, and follow-up data of SUA fetuses diagnosed by ultrasound examination at 11~13⁺⁶ weeks at Chongqing Health Center for Women and Children/Women and Children's Hospital of Chongqing Medical University from April 2017 to April 2019 were retrospectively analyzed. According to other ultrasound structural abnormalities combined, the patients were divided into either an isolated SUA group or a non-isolated SUA group. Enumeration data between the two groups were compared by the t test, and measurement data were compared by the χ² test.

Among 433 cases diagnosed with SUA by ultrasound at 11~13⁺⁶ weeks, those who did not conform to the SUA diagnosis by later review (n=31) and those who were lost to follow-up (n=42) were excluded, and a total of 360 patients met the SUA diagnosis, with a diagnostic accuracy of 92.1% (360/391). And 271 cases whose chromosome results were obtained were finally included. There were 202 (74.54%) cases of isolated SUA and 69 (25.46%) cases of non-isolated SUA; there was no statistical difference in general data between the two groups (P＞0.05). There were 4 cases (1.98%, 4/202) of isolated SUA and 9 (13.04%, 9/69) cases of non-isolated SUA in the 13 fetuses with chromosomal abnormalities, and the latter group contained 1 (5.88%, 1/17) case with other abnormal soft indicators, 4 (11.43%, 4/35) cases with single malformation, and 4 (23.53%, 4/17) cases with multiple malformations; the differences between the 4 groups were statistically significant (χ²=19.99, P=0.002). Combined malformations were mainly malformations of the cardiovascular system, genitourinary system, and nervous system.

The accuracy of prenatal ultrasound in the diagnosis of single umbilical artery in early pregnancy is high. SUA is associated with chromosomal abnormalities in the fetus. The proportion of chromosomal abnormalities in isolated SUA is low. Non-solitary SUA chromosome abnormality has a high incidence, and the possibility of chromosome abnormality in fetuses with more complicated malformations is greater. When single umbilical artery is found by prenatal ultrasound in early pregnancy, doctors should be cautious of other soft indicators and malformation.