First Trimester Umbilical Cord and Vessel Diameters of Thai Fetuses
Chadakarn Phaloprakarn MD*, Vorapong Phupong MD*, Yuen Tannirandorn MD*, Boonchai Uerpairojkit MD*, Dhiraphongs Charoenvidhya MD*, Teera Wacharaprechanont MD*
Affiliation : * Department of Obstetrics and Gynaecology, Faculty of Medicine, Chulalongkorn University
Objective : To establish the reference ranges for first trimester umbilical cord and vessel diameters of Thai
fetuses.
Materials and Methods : A prospective study was performed on normal pregnant women between 10+0 and 13+6
weeks of gestation who underwent ultrasound examination. The diameter measurements were obtained by
a 7.5 MHz vaginal - or a 3.75 MHz abdominal transducer. Statistics were analyzed using SPSS computer
program.
Results : Records of 184 pregnancies were analyzed and the outcome demonstrated a strong correlation
between umbilical cord diameter and gestational age (r = 0.90; p < 0.001). Umbilical vessel diameters were
also correlated with gestational age.
Conclusion : First trimester umbilical cord and vessel diameters of Thai fetuses are related to gestational
age. The presented reference ranges might be useful for further studies, such as prediction of adverse preg-
nancy outcome or combination with biochemical or other ultrasound markers for fetal aneuploidy
screening.
Keywords : Diameter, Umbilical cord, Umbilical vessels, First trimester, Thai fetuses
