To explore clinical evaluation of fetal prognosis of single umbilical artery (SUA) with other congenital structural malformations.

From January 1, 2014 to December 31, 2020, a total of 1 160 fetuses of SUA revealed by ultrasonic examination among pregnant women in the second and third trimester of pregnancy in Guangzhou Women and Children′s Medical Center were included. According to SUA with other congenital structural malformations or not, they were divided into observation group (n=175, SUA with other congenital structural malformations) and control group (n=985, isolated of SUA). Clinical data of pregnant women and SUA fetuses were retrospectively analyzed. Chi-square test and rank sum test were used to compare fetal chromosomal abnormalities rate, pregnancy outcomes and situations of live births at birth, etc. between 2 groups. This study was approved by the Ethics Committee of Guangzhou Women and Children′s Medical Center (Approval No.[2019] 11600). All pregnant women gave informed consent to all examinations and signed the informed consent forms for clinical research.

① In observation group, there were a total of 239 other congenital structural malformations among 175 SUA fetuses. According to involved system of congenital structural malformations and its proportion, the top three systems were cardiovascular malformations (43.5%, 104/239), urogenital malformations (17.5%, 42/239) and digestive malformations (15.1%, 36/239). ② There were 25 fetuses with chromosome anomalies among 1 160 SUA cases, and chromosome abnormality rate was 2.2%. Chromosome abnormality rate in observation group SUA fetuses was 11.4% (20/175), which was significantly higher than that in control group (0.5%, 5/985), and the difference was statistically significant (χ²=84.046, P<0.001). In observation group, chromosome abnormality rate of SUA fetuses with multiple congenital structural malformations was 20.0% (10/50), which was significantly higher than that of SUA fetus with single congenital structural malformation (8.0%, 10/125), and the difference was statistically significant (χ²=5.081, P=0.024). ③ Follow-up results showed that constituent ratio of live birth, late abortion, intrauterine death and selective termination of pregnancy of fetus in observation group and control group were 84.6% and 98.5%, 1.1% and 0.1%, 4.0% and 1.2%, 10.3% and 0.2%, respectively. There was significant difference of constituent ratio of above pregnancy outcomes between two groups (χ²=69.287, P<0.001). ④ The gestational age at birth and birth weight of live birth infants in observation group were 38 weeks (36 weeks, 39 weeks) and 2 820 g (2 240 g, 3 245 g), respectively, which were smaller or lower than those of 39 weeks (38 weeks, 40 weeks) and 3 200 g (2 560 g, 3 470 g) respectively in control group; while proportions of premature infants and small for gestational age infants in observation group were 14.9% and 20.3%, respectively, which were higher than those of 3.7% and 9.7% respectively in control group, and all differences above mentioned were statistically significant (Z=-8.019, -4.610; χ²=32.476, 14.575; all P<0.001).

For pregnant women with SUA fetus should be dynamic detected intrauterine growth indicators by routine fetal ultrasound, and for pregnant women with fetal SUA and other congenital structural malformation detected by ultrasound, further prenatal diagnosis should performed to evaluate fetal outcome, and take timely measures to reduce birth of a fetus with birth defects.