Comparison of perinatal outcome in fetuses with reverse or absent enddiastolic flow in the umbilical artery and/or fetal descending aorta.

OBJECTIVES

To examine the differences of perinatal outcome in fetuses with absent and reversed enddiastolic flow velocity waveforms of the umbilical artery or fetal descending aorta.

DESIGN

In a retrospective study, 30 pregnant women with reversed enddiastolic flow in the umbilical artery or fetal aorta (group I) were compared with 30 cases of absent enddiastolic flow (group II). Patients were included in the groups according to the last Doppler finding before delivery. Perinatal and neonatal outcome was correlated with antenatal Doppler flow findings.

RESULTS

The mean gestational age at birth was 31 weeks in both groups. Fetuses with reverse flow showed higher perinatal (27% and 7% respectively) and overall mortality (53.3% and 10% respectively) compared to the absent enddiastolic flow group (p < 0.05). All the intrauterine fetal deaths occurred in the reversed flow group (n = 12). The rates of intrauterine growth retardation, oligohydramnios and hypocalcemia were different between the groups (p < 0.05). The cesarean section rate, perinatal and neonatal complications including the incidence of acidosis, the number of cases admitted to neonatal intensive care unit and mean treatment time were not different between the groups. A tendency to higher incidence of neonatal cerebral hemorrhage in reversed flow cases (28%) compared to absent enddiastolic flow cases (17%) was observed, but this was not statistically significant.

CONCLUSIONS

The present study suggests that reversed flow should be seen as a particular clinical entity with higher incidences of perinatal and overall mortality, and severe intrauterine growth retardation (< 5. perc) compared to the absent enddiastolic flow group. The optimal timing of delivery in pregnancies complicated by highly pathological Doppler flow findings is only to be resolved in well-designed randomized, multicenter clinical trials.