Doppler blood velocity waveforms in the umbilical artery as an indicator of fetal well-being

Doppler blood velocity waveforms were analyzed from the umbilical artery as an indication of fetal well-being. Since the ratio of systolic to diastolic peak flows (A/B) reflects placental vascular resistance, an abnormality of this value may accurately predict compromised fetuses. Twenty-one studies were performed on 13 patients, using a new duplex system for real-time imaging and range-gated pulsed Doppler analysis, and compared to normal standards. Thirteen studies done in nine uneventful pregnancies were consistently normal. However, abnormal studies were found in the four patients reported as case histories, including women with sickle cell anemia, systemic lupus, diabetes, and growth retardation. The A/B ratio was felt to have predicted potential fetal compromise, including the two fetal deaths. Therefore, with certain cautions, we feel that this rapid, non-invasive technique is useful as a serially applicable reflector of the status of fetoplacental circulation.