Placental Doppler velocimetry in gestational diabetes mellitus

Objective: To evaluate if maternal glucose level and growth of the fetus were related to placental vascular impedance in pregnancy complicated by gestational diabetes mellitus. Material and methods: A retrospective study of 146 gestational diabetic women of which 117 needed insulin therapy. Glycosylated hemoglobin (HbA(1c)) was evaluated as well as umbilical and uterine artery Doppler velocimetry. The results were related to adverse outcome of pregnancy including newborn birthweight. Results: Abnormal umbilical artery blood flow velocity was seen in 5% of the cases and abnormal uterine artery flow in 16%. Uterine and umbilical artery vascular impedance was significantly lower in macrosomic newborns. There was a poor correlation between HbA(1c), vascular impedance and birthweight. There were 11 cases that developed preeclampsia, all having abnormal uterine artery Doppler and two abnormal umbilical artery Doppler. Conclusion: Uterine and umbilical artery vascular impedance in pregnancies complicated by gestatinal diabetes is related to birthweight and placental weight, but not to maternal HbA(1c) levels. Placental Doppler ultrasound does not seem to be of clinical value for fetal surveillance in these pregnancies unless the pregnancy is complicated by preeclampsia and/or intrauterine fetal growth restriction.