Absent end-diastolic velocity in the umbilical artery and its clinical significance

Abstract

It is apparent from cumulative experience that the end-diagnostic component of the umbilical arterial Doppler waveform is of crucial importance for fetal prognostication. AREDV is known to be associated with an unusually adverse perinatal outcome. Most remarkably, these infants suffer from high perinatal mortality and morbidity rates and demonstrate an increased frequency of malformations and chromosomal abnormalities, with a predominance of trisomies 13, 18, and 21. Most infants with AREDV require intensive care. Furthermore, the risk of cerebral hemorrhage, anemia, and hypoglycemia is increased. It has been observed, however, that absent end-diastolic flow may improve, although often only transiently, and that weeks or more may elapse before the fetus shows additional evidence of compromise. Obviously, the presence of absent end-diastolic flow should warn the physician of significantly increased fetal risk. Appropriate surveillance measures should be immediately undertaken. If the pregnancy is significantly preterm, consideration for delivery should include additional signs of fetal compromise. A more aggressive approach should be taken to ensure fetal maturity. If fetal anomalies are present or AEDV cannot be explained by pregnancy complications such as preeclampsia, then fetal karyotype should also be determined to rule out lethal aneuploidies. Although the benefits of emergency delivery for this phenomenon remain controversial, randomized clinical trials have shown improved outcome from intervention in pregnancies with absent end-diastolic velocity. This subject is discussed comprehensively in Chap. 26. © 2005 Springer-Verlag Berlin Heidelberg.