Doppler Study of Umbilical Artery in Thai Fetus
Anuwat Sutantawiboon MD*, Saifon Chawanpaiboon MD*
Affiliation : * Department of Obstetrics and Gynaecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : Create reference centile charts for Doppler study of Pulsatile index (PI), Resistance index (RI) and Systolic to
Diastolic (S/D) ratio of umbilical artery in Thai fetus throughout gestation.
Material and Method: Six hundred fifty eight pregnant women between 13-40 weeks gestation who attended the antenatal
clinic at Siriraj Hospital, Mahidol University, Bangkok, were recruited. Each fetus was measured only once for the purpose
of the present study. The mean and fitted centiles were estimated at each week of gestation using linear regression modeling.
Results : Doppler study of Pulsatile index (PI), Resistance index (RI), and Systolic to Diastolic (S/D) ratio of umbilical artery
were measured in 658 fetuses. The mean 95% confidence intervals for Doppler study of Pulsatile index (PI), Resistance index
(RI), and Systolic to Diastolic (S/D) ratio of umbilical artery at each gestational age were fitted to estimate by linear regression
models. The centile chart of this parameter was also presented.
Conclusion : Reference centile chart for Doppler study of Pulsatile index (PI), Resistance index (RI) and Systolic to Diastolic
(S/D) ratio of umbilical artery of Thai fetuses was presented.
Keywords : Pulsatile index (PI), Resistance index (RI), Systolic to Diastolic (S/D) ratio, Umbilical artery, Centile chart
