Ultrasonic identification of pump twin by dual-gate Doppler in a monochorionic-triamniotic triplet twin reversed arterial perfusion sequence before preventative radiofrequency ablation: a case report.

We performed a dual-gate Doppler examination for a twin reversed arterial perfusion (TRAP) sequence in a monochorionic-triamniotic triplet pregnancy at 16 weeks of gestation and were able to identify the pump twin by arterial pulse rate synchronicity. We performed radiofrequency ablation to coagulate blood flow in the acardius at 16 weeks of gestation without any postoperative complication. At 29 weeks of gestation, we performed a cesarean section due to preterm rupture of the membranes and the patient delivered 1167/1237-g female neonates and a macerated acardius. Examination of the placenta revealed two thickened vessels from the pump twin to the acardius, which had been prenatally identified by dual-gate Doppler. This new technology launches the new field of noninvasive fetal identification for triplet TRAP sequence.