Objective: To evaluate the ratio of peak systolic to least diastolic flow velocity (S/D), pulsatile index (PI) and resistance index (RI) of the umbilical arterial doppler flow at 20-40 gestational weeks in twin pregnancy for the surveillance of twin transfusion syndrome.
Methods: The fetal hemodynamics in 36 cases of twin pregnancy were monitored by Combison A-ZIPE 4871 with spectral doppler ultrasound.
Results: The value of S/D ratio and PI in 4 patients with twin transfusion syndrome at 32-34 weeks were significantly higher than those of normal twin (P < 0.01). Two cases of twin reversed arterial pressure (TRAP), i.e. artery to artery transfusion in one of the twin with acardius, were found at 26 and 26 + 4 weeks respectively.
Conclusion: The S/D ratio and PI of umbilical artery might be useful indices for the surveillance of twin transfusion syndrome.