P13.10: Sonographic measurement of the diameter and blood volume of umbilical vessels during mid‐trimester to predict small‐for‐gestational age

Abstract

The objective of this study was to evaluate the diameter, blood velocity and blood volume of umbilical artery and vein using ultrasonography during mid-trimester of pregnancy to predict small for gestation age (SGA) at delivery. This study was performed in 104 low-risk pregnancies. Diameter, blood velocity and blood volume of umbilical artery and vein were measured between 20 and 25 weeks of gestation using ultrasonography and we checked the fetal birhweight among full term deliveries. We evaluated the reference value of its parameter during mid-trimester and analyzed the useful parameter to predict SGA at delivery. The mean diameter and blood volume of umbilical artery were increased according to gestational age from 20 to 25 weeks (r = 0.5678, p < 0.0001 and r = 0.4920, p < 0.0001, respectively), but the mean blood velocity of umbilical artery was not changed. The mean diameter and blood volume of umbilical vein were also increased according to gestational age (r = 0.7465, p < 0.0001 and r = 0.5837, p < 0.0001, respectively), but the blood velocity of umbilical vein was decreased without significance. SGA at delivery were 10 pregnancies (9.6%). Among its parameter during mid-trimester pregnancies, umbilical vein diameter was most predictable parameter to predict SGA (AUC = 0.769, p < 0.0001), and umbilical artery diameter and blood volume, and umbilical vein blood volume were also predictable for SGA. Diameter and blood volume of umbilical vessels are increased according to gestational age in low-risk pregnancies, but blood velocity of its vessels are not changed. Mid-trimester umbilical vein diameter seems to useful parameter to predict future SGA at delivery, although more additional parameters are related to fetal growth.