Abnormal internal carotid and umbilical artery Doppler in the small for gestational age fetus predicts an adverse outcome

Doppler studies of the internal carotid and umbilical arteries were performed in 29 women admitted to the antenatal ward with a diagnosis of being small for gestational age. The primary aim of the study was to determine whether an abnormal internal carotid waveform was associated with a poor perinatal outcome defined as: fetal distress, acidosis at birth or perinatal death. A poor perinatal outcome occurred in 18 pregnancies including six perinatal deaths. There was a highly significant association between an abnormal internal carotid waveform and a poor outcome and this was particularly so at a gestational age of ≤ 34 weeks where the sensitivity, specificity and predictive values were all 100%. No baby with a normal internal carotid waveform had a poor outcome. Abnormal umbilical waveforms tended to occur earlier in pregnancy than abnormal internal carotid waveforms and were also predictive of an adverse perinatal outcome. Whether this information should be used clinically is not clear as abnormal umbilical artery and internal carotid waveforms were sometimes present for weeks before delivery occurred for fetal reasons.