Hyperglycaemia can alter placental resistance to blood flow and hyperglycaemia has adverse perinatal outcomes. Oral glucose tolerance testing (OGTT) increases the maternal plasma glucose levels temporarily and mimics metabolic hyperglycaemia. The blood flow of the uterine artery (UtA), umbilical artery (UA), middle cerebral artery (MCA) were assessed before, 1 and 2 h following the OGTT by using Doppler ultrasonography. Z-score of cerebroplacental ratio (CPR), pulsatility index (PI) for three vessels were evaluated separately. All measurements of the MCA, UA, UtA Doppler parameters were not statistically different for fasting, and 1 and 2 h following the 75 g OGTT in the 53 pregnant women with a singleton gestation in the low-risk group. This study results show that acute hyperglycaemia induced by OGTT has no effect on maternal and foetal Doppler parameters in healthy pregnancies.IMPACT STATEMENT