Study of Maternal and Fetal Doppler Velocimetry, Histopathology of Placental Bed in Diabetic Pregnancy and Its Correlation to Fetal Outcome

Diabetes mellitus still represents an important medical problem during pregnancy, causing perinatal morbidity and mortality. Despite improved outcome reflected by a steep decline in perinatal mortality over the past few decades, controversy still exists regarding the care of the pregnant woman with both pre-existing and gestational Diabetes Mellitus. Doppler ultrasound is especially valuable during pregnancy because fetal maternal and placental circulations can be studied. The aim of this work was to study the vascular changes in the uteroplacental and fetoplacental circulations, and to correlate these findings with histopathology of the placenta and placental bed, which may occur in association with diabetic pregnancies. The study was carried out on 100 pregnant women of comparable age and parity. They were divided into 2 groups. The control group comprising 20 normal non-diabetic pregnant women and the normotensive diabetic group comprising 80 pregnant diabetic women. All were singleton pregnancies of 34 weeks or more and were delivered by C.S the control and the study cases were subjected to history taking and thorough physical examination. They were also subjected to ultrasonographic examination for fetal biometric parameters and for Doppler examination. Doppler examination included umbilical artery, uterine arteries fetal middle cerebral artery. At the time of C.S the placenta and placental bed biopsy was obtained. After delivery, the Apgar score of the newborn was assessed at 1 and 5 minutes, the body weight was measured, and the fetus was followed up for any complications. Result: There was a positive correlation between the umbilical artery PI and the mean blood glucose levels indicating that poor diabetic control is probably associated with increased umbilical artery PI. However, there was no significant difference between the mean value of the umbilical artery PI in the diabetic and control groups. The uterine arteries Doppler indices showed no significant findings between the diabetic and the control groups. Neither did the uterine arteries Doppler indices show a correlation with the mean blood glucose levels. There was no significant difference between the middle cerebral artery PI in the diabetic and control groups. This observation indicates that there was no redistribution in the fetal circulation in the fetuses of the diabetic group. There was also non correlation between the MCA Doppler indices and the glycemic control. Histopathologic studies of the placental bed showed marked difference between the diabetic group and the control group as regards lack of physiologic changes and arteriosclerotic changes, which emphasizes the effect of diabetes on the placental bed vasculature. Conclusion: Abnormal umbilical artery waveform analysis is one of significant predictors of fetal compromise in diabetic pregnancy, but fetal compromise can occur in association with normal Doppler waveform analysis. In maternal diabetes the classic redistribution seen in fetal hypoxemia due to uteroplacental insufficiency may not occur in diabetic patient even in severely compromised fetuses. In maternal diabetes mellitus, maternal glycemic control has no effect on impedance to flow in the uterine and middle cerebral arteries. No relationship was found between the uterine or umbilical arteries Doppler indices and the placental bed decidual vascular pathology in diabetic pregnancies. There was no correlation between placental findings and the Doppler waveform analysis of the umbilical and the uterine arteries.