Relevance of routine Doppler sampling at the two umbilical arteries in the follow-up of dichorionic twin pregnancies with intrauterine growth-restricted fetuses.

OBJECTIVE: The aim of this study is to assess if the presence of bilateral absent or reverse end-diastolic velocity (AREDV) indicates a poorer prognosis than unilateral AREDV in dichorionic-diamniotic twin pregnancies complicated by intrauterine growth restriction.

METHODS: A prospective observational study of 36 dichorionic-diamniotic twin pregnancies complicated by intrauterine growth restriction. One hundred and fifty seven ultrasound (US) examinations were performed. The pulsatility indexes (PI) of the two umbilical arteries (UA-perivesical site), the middle cerebral artery (MCA) and the ductus venosus (DV) were recorded. The fetal hemodynamic status was represented by the existence of a bilateral positive end-diastolic velocity (PEDV), a unilateral AREDV or a bilateral AREDV in the umbilical arteries.

RESULTS: Bilateral PEDV, unilateral AREDV and bilateral AREDV represented respectively 66.0%, 10.6% and 23.4% of the US examinations. Intervals between Doppler examinations and delivery were significantly longer (P<0.005) in the bilateral PEDV group (26.5 days±19.7) than in the unilateral AREDV group (11.8 days±11.7) and in the bilateral AREDV group (11.0 days±8.6). MCA-PI, DV-PI, IFI and early neonatal outcomes did not differ between the unilateral and bilateral AREDV groups.

CONCLUSION: The routine measurement of the Doppler indices of the two umbilical arteries seems to be no more relevant than unilateral measurement in fetuses of dichorionic-diamniotic twin pregnancies complicated by intrauterine growth restriction.