Prediction of fetal outcome by Doppler examination and by the non‐stress test

Abstract

Ninety-four women with high-risk pregnancies were referred to the Aker University Hospital, Department of Obstetrics, and monitored by Doppler velocimetry and conventional cardiotocography. The peak systolic/end diastolic (A/B) ratio was measured in the velocity waveform obtained in the umbilical artery blood flow. The non-stress test (NST) was classified according to the Fischer scores. In this mixed group of high-risk pregnancies, the sensitivity of the A/B ratio to predict fetal growth retardation was 71%, predictive value 57% and specificity 77%. The corresponding values for NST were 39%, 65% and 90%. It is concluded that Doppler velocimetry is more sensitive than cardiotocography for identifying fetal growth retardation. In an attempt to further improve the detection rate of fetal pathology, the cases with abnormal NST scores were added to those with high A/B ratios and collectively defined as abnormal. In consequence, only an insignificant improvement in sensitivity (79%) could be achieved. When the A/B ratio is normal, there seems little justification for expending time, effort and resources in routine use of cardiotocography.