[Complex umbilical cord vein pulsations in cases with twin-twin transfusion syndrome: prognostic implications]

Umbilical vein pulsations (UV-P) are due to various etiologies. The aim of the present study was to investigate the incidence and type of UV-P in monochorionic twins with twin-twin transfusion syndrome (TTTS).

TTTS cases diagnosed between 1999 and 2009 were examined retrospectively. The UV flow pattern taken from a free floating loop of the umbilical cord was classified as "non-pulsatile" (NP), "monophasic" (MP) and "complex" (CP). Only Doppler flow analyses prior to intervention were examined.

Of 106 cases seen during the study period, 56 cases met the inclusion criteria. Of those, 62.5% were classified as stage III TTTS, and fetoscopic laser therapy was performed in 45 cases. NP flow patterns were more likely found in the donor twin (80.4 vs. 28.6%; p < 0.0001), while the incidence of MP (50 vs. 17.9%; p < 0.0006) and CP flow patterns (21.4 vs. 1.7%; p < 0.01) was higher in the recipient twin. Moreover, the perinatal mortality was highest in cases with CP (CP: 76.9 vs. MP 42.1 vs. NP: 26.2%; p < 0.01) as well as the rate of cases with double death.

CP patterns are more frequently found in the recipient twin and are associated with a considerably high mortality rate. Studying the umbilical vein flow pattern in TTTS may provide additional information for counseling and prognosis similar to that obtained by expensive fetal echocardiography.