Doppler Sonographic Characteristics of Umbilical and Uterine Arteries during Oral Glucose Tolerance Testing in Healthy Pregnant Women

Purpose. Studies have shown that maternal hyperglycemia may be associated with increased placental resistance to blood flow and possibly adverse perinatal outcomes. The aim of this study was to determine whether Doppler velocimetric dynamics change in the uterine and umbilical arteries in healthy pregnant women (without gestational diabetes) during acute hyperglycemia induced by oral glucose tolerance testing. Methods. Flow in the umbilical and right and left uterine arteries was assessed by spectral Doppler sonographic examination of healthy pregnant women at 24-28 weeks' menstrual age. Four Doppler studies were conducted for each woman: 1 before oral administration of 100 g of glucose and 3 more at 1, 2, and 3 hours after glucose administration. The systolic-to-diastolic ratio was calculated for the umbilical artery, and the resistance index was calculated separately for the left and right uterine arteries. Results. All results of oral glucose tolerance testing were normal, and Doppler signals were obtained in all 30 patients enrolled. No abnormal systolic-to-diastolic ratios or resistance indices were detected in any of the examinations. No significant differences in waveforms or resistance indices between the right and left uterine arteries were found during the various testing intervals. Conclusions. Acute hyperglycemia induced in healthy pregnant women does not affect blood flow velocimetric characteristics in the umbilical or uterine arteries at any stage of oral glucose tolerance testing.