Prenatal and neonatal outcomes of pregnancies diagnosed with fetal single umbilical artery

Abstract

Objective To investigate the associated anomalies and outcomes of fetuses diagnosed as having a single umbilical artery (SUA) which were reported inconsistently in previous studies. Methods The data of 82 pregnancies with fetal SUA, 35 of which were complex, and 47 isolated SUA (iSUA) and 100 pregnancies with fetal double umbilical arteries (DUA) between June 2018 and July 2020 were retrieved. We compared the maternal characteristics, and pregnancy and fetal outcomes of the three groups (iSUA, SUA, and DUA). Results Of 82 fetuses with SUA, 35 had 64 major structural abnormalities. 20 of these 35 fetuses (57.1%) had cardiovascular malformations, 12 (34.2%) had central nervous, 10 (28.5%) had genitourinary, and eight (22.8%) had gastrointestinal system malformations. Isolated SUA was present in SUA. Compared with the 100 DUA fetuses, SUA was a risk for intrauterine growth restriction (IUGR), preterm delivery, Apgar scores of <7, and admission to the neonatal intensive care unit. Having fetal chromosomal or structural abnormalities, was a risk for amnion fluid abnormality, pregnancy termination, intrauterine fetal death, early neonatal death, and a low live birth ratio in SUA cases. Conclusion SUA has an increased rate of fetal structural and chromosomal abnormalities. Among them, the most detected one is cardiac and the second most common one is central nervous system malformations. Pregnancies with fetal SUA have increased risk for IUGR, preterm delivery, low Apgar scores, and admission to the neonatal intensive care unit. The presence of additional structural or chromosomal malformations increases the rate of these adverse pregnancy risks. Thus, these cases warrant dedicated fetal ultrasonographic organ screening and close prenatal follow-up.