BLOOD SUPPLY OF FETAL KIDNEYS IN SERIOUS DEGREE PLACENTAL FAILURE

Purpose: To study a state of renal hemodynamics at placental failure of a serious degree.

Methods and Materials: The echographic examination of 23 women with placental failure of serious degree (absent or reversal diastolic flow in the umbilical artery) and 178 with physiological pregnancies in terms of 28–40 weeks was carried out. Doppler examination included blood flow velocity waveform assessment in uterine arteries, umbilical arteries, dextral and left renal fetus arteries with calculation of the peak systolic, end diastolic velocities, systolic-diastolic and resistance indexes.

Results: In placental failure of serious degree in renal arteries end diastolic velocity was significantly lower in compare with the physiological pregnancy (2.3±1.6 and 7.5±2.4 accordingly, p<0.05). In 47.8% (11) cases there was no diastolic or end diastolic flow in renal arteries. But there was not found reliable changes in peak systolic velocities (48.4±3.1 and 53.7±4.3 accordingly, p<0.05). The reliable increasing of resistance index in renal arteries was found in placental failure of serious degree in compare with the physiological pregnancy (S/D –11.2±3.3 and 7.3±1.5 accordingly, p<0.05; RI –0.95±0.03 and 0.86±0.02 accordingly, p<0.01). There was no reliable difference between parameters of blood flow velocities in right and left renal arteries. In 65% (15) cases an oligoamnios was marked.

Conclusions: The significant renal arteries diastolic flow velocities decreasing, resistance indexes increasing and the oligoamnios in placental failure of serious degree are the result of fetal kidneys blood supply intensity decreasing, which is related to centralization of a blood circulation and high peripheral vascular resistance.