Outcomes of severely abnormal umbilical artery doppler velocimetry in structurally normal singleton fetuses

To construct a management guide for preterm pregnancies complicated by severely abnormal umbilical artery Doppler velocimetry.

A retrospective chart review was conducted on all cases of absent or reversed end-diastolic flow umbilical artery Doppler velocimetry identified through an ultrasound data base. Maternal and perinatal outcome variables were retrospectively reviewed and analyzed using both parametric and nonparametric statistical techniques. Seventy-one cases were identified over a 5-year period. After excluding multiple gestations, anomalous fetuses, and two cases that were terminated before 24 weeks' gestation, 56 singleton gestations remained for analysis.

Among the 56 subjects, there were 45 survivors and 11 deaths (five fetal and six neonatal deaths). Nonsurvivors had a significantly lower gestational age at diagnosis and delivery. Nonsurviving live-born neonates had lower Apgar scores and were significantly smaller; however, there were no differences in proportion or severity of fetal growth restriction in survivors and nonsurvivors. There were no differences in last biophysical profile before delivery or interval from diagnosis of reversed end-diastolic flow to delivery. Predictors of nonsurvival were the presence of reversed end-diastolic flow and oligohydramnios. Perinatal mortality for reversed end-diastolic flow was 333/1000 and 94/1000 for absent end-diastolic flow. Risk for perinatal death was highly gestational age dependent. For delivery at less than 26 weeks, survival was one of four; at 26-27.9 weeks, survival was seven of 12; and at 28 weeks or greater, survival was 37 of 40.

Whereas severely abnormal umbilical artery blood flow poses significant risk for pregnancy, perinatal mortality is dominated by gestational age at diagnosis and delivery. This may reflect the severity of the disease or the low survival of very immature gestations. Interventions on behalf of the fetus at very early gestational ages should be undertaken with caution.