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.