P04.04: Compensatory dilatation of umbilical arterial diameter in isolated single umbilical artery: Poster discussion hub abstracts

The aim of this study is to evaluate differences of umbilical arterial diameter (UmAD) and Doppler velocimetry on umbilical artery between fetuses with isolated single umbilical artery (iSUA) and fetuses with three vessel cord (TVC). We retrospectively reviewed 118 cases of ultrasonographic exam of fetuses from 28 to 32 weeks of gestation with a prenatally identified iSUA and without congenital malformation retrospectively, who are delivered in Severance Hospital, Yonsei University Health System. UmAD and Doppler velocimetry including presystolic velocity, end-diastolic velocity, RI, and systolic-diastolic ratio on umbilical artery of both group were reviewed. Thirty fetuses with prenatally identified iSUA were enrolled and twelve fetuses was revealed small-for-gestational age (SGA) after delivery. Eleven out of ninety fetuses without any congenital malformation were confirmed in SGA after delivery. Doppler velocimetry didn't make differences in both group. However, significant difference of UmAD was apparent between iSUA group and TVC group. UmAD in iSUA group without SGA is significantly greatest comparing with iSUA with SGA group, TVC with or without SGA groups. In iSUA group, 3.45 mm of UmAD had 76.5 % of sensitivity and 91.7 % of specificity to predict SGA. Normal fetuses with iSUA are at higher risk to be born as SGA. With our study results we can confirm the hypothesis that compensatory dilatation of umbilical arterial diameter in fetuses with iSUA while Doppler velocimetry doesn't have significant differences between iSUA and 3VC group. And UmAD could be a useful predictor of SGA with fetuses with iSUA.