FETAL ACIDOSIS AND DOPPLER VELOCIMETRY OF THE UMBILICAL ARTERIES IN LABOR

The objective of the study was to determine whether Doppler velocimetr y indices of the fetal umbilical arteries change with the development of acidosis during labor. Repeated Doppler velocimetry was performed i n selected patients with high-risk labors for the purpose of evaluatin g whether this might be a useful test of fetal well-being in labor. Th e study sample comprised 36 women with singleton pregnancies, complica ted either by gestational proteinuric hypertension or by intrauterine growth retardation (or both) with a normal cardiotocographic tracing a t the onset of labor. The acid-base status of the fetus was assessed a fter delivery by analyzing the umbilical artery blood A total of 27 fe tuses were followed through labor. Six were born with an umbilical art ery base deficit of more than 10 mmol/l. No change in mean Pourcelot r atio (resistance index) was noted in both normal and acidotic fetuses. None of the acidotic fetuses showed a change in Pourcelot ratio of mo re than 0.03. We conclude that Doppler velocimetry of the umbilical ar teries, as measured by the Pourcelot ratio, does not contribute to the diagnosis of fetal acidosis in labor.