The Ratio of Umbilical Venous to Umbilical Arterial Diameter in the Second Trimesters Efficiently Predicts the Perinatal Outcome

  • Hyun Young Ahn, Department of Obstetrics and Gynecology, the Catholic University of Korea, Korea
  • Se Kyung Choi, Department of Obstetrics and Gynecology, the Catholic University of Korea, Korea
  • Jeong Su Choi, Department of Obstetrics and Gynecology, the Catholic University of Korea, Korea
  • Ji Seon We, Department of Obstetrics and Gynecology, the Catholic University of Korea, Korea
  • Yeon Hee Kim, Department of Obstetrics and Gynecology, the Catholic University of Korea, Korea
  • Guisera Lee, Department of Obstetrics and Gynecology, the Catholic University of Korea, Korea
  • Sa Jin Kim, Department of Obstetrics and Gynecology, the Catholic University of Korea, Korea
  • Jong Chul Shin, Department of Obstetrics and Gynecology, the Catholic University of Korea, Korea

    • Objectives: To assess the association the ratio of umbilical umbilical venous to umbilical arterial diameter in the second trimester and perinatal outcome including perinatal death, intrauterine growth restriction (IUGR), macrosomia, preterm/post-term delivery and pre-eclampsia.
    Methods: We retrospectively studied 526 pregnant women between 19+0 to 23+6 weeks' gestation with singletons pregnancy. We measured the diameter of umbilical cord vein and artery. Patients with umbilical cord measurements below the 5th percentile were defined as thin umbilical cord group and those between the 5th and 95th or above 95th percentile were divided. We estimated the ratio of umbilical venous to umbilical arterial diameter. Fetal demise, preeclampsia, mode of delivery, gestational age at delivery, birth weight, and 5-min Apgar scores were noted. Odds ratios (OR) and 95% CIs for adverse outcome were calculated.
    Results: The relative risk of the adverse perinatal outcome in thin umbilical cords was 3.14 (1.51–6.34; 95% CI). Fetuses with lower ratio of umbilical venous to umbilical arterial diameter is associated with poor perinatal outcome such as IUGR ( OR of 3.55, 95% CI, 1.21-8.56), perinatal death ( OR of 2.34, 95% CI, 1.17-5.65), and preterm delivery ( OR of 2.78, 95% CI, 1.34-5.54).
    Conclusions: There is a significant relationship between the diameter of umbilical cord and adverse pregnancy outcome. Sonographic finding of a thin umbilical cord in the second trimester should prompt the physician to strict monitoring of pregnancy.