Recipient's vascular doppler pattern immediately following death of the donor in a case of untreated severe twin-to-twin transfusion syndrome.

In a stage III twin-to-twin transfusion syndrome, death of the donor at 31 weeks was followed by unusual umbilical artery (UA) doppler findings in the recipient, with a high diastolic peak velocity and a low S/D ratio. Besides, middle cerebral artery waveforms could not be obtained in the recipient. The recipient was delivered by emergency cesarean section, weighed 1,230 g, was strikingly pale and had a cord hemoglobin concentration of 15 g/dl. Neonatal blood average pressure was of 29 mm Hg, immediately after delivery, and ranged from 33 to 43 mm Hg in the first 12 h of life. Neonatal heart function returned to normal on day 2. We hypothesize that death of the donor twin induced an acute decrease in placental resistance. This phenomenon, combined with decreased systolic blood flow due to the recipient's systolic function impairment, could account for the umbilical artery flow pattern we observed. The acute decrease in volemia and the presence of systemic hypertension and cardiomyopathy may explain the inability to obtain middle cerebral artery doppler. This complex hemodynamic disturbance in the recipient may be responsible for morbidity unrelated to anemia in case of donor's demise, as acute fetal distress.