The clinical significance of Doppler umbilical artery velocimetry in the small for gestational age fetus.

Fifty-four women who were delivered of small for gestational age infants were studied antenatally by serially continuous-wave Doppler velocimetry. Outcomes were compared in the normal and abnormal systolic/diastolic ratio groups. Seventy-eight percent had an abnormal systolic/diastolic ratio. The group with an elevated systolic/diastolic ratio had a significantly higher incidence of abnormal fetal heart rate, pregnancy-induced hypertension, oligohydramnios, cesarean section for fetal distress, and admission into the neonatal intensive care unit. One third of the newborns required intermittent positive pressure ventilation. Average birth weight and gestational age at delivery were significantly lower and there were six perinatal deaths in the group with an elevated systolic/diastolic ratio and none in the group with a normal systolic/diastolic ratio. These data suggest that the small for gestational age fetus with normal umbilical artery velocimetry is at significantly lower risk than are those with abnormal ratios. This implies that management of the small for gestational age fetus may now be aided by a functional classification based on the umbilical artery velocity waveform.