PRENATAL DETECTION OF ISCHEMIC CHANGES IN THE PLACENTA OF THE GROWTH-RETARDED FETUS BY DOPPLER FLOW VELOCIMETRY OF THE MATERNAL UTERINE ARTERY

Objective: To determine the relationships among the pregnancy outcomes of growth-retarded fetuses, Doppler flow velocimetry of the fetomater nal circulation, and pathologic changes in the placenta. Methods: Fort y-seven fetuses confirmed to be growth-retarded by ultrasonographic bi ometry were monitored during pregnancy in terms of the resistance inde xes of the maternal uterine, fetal umbilical, and fetal middle cerebra l arteries. After delivery, the placentas were examined for pathologic changes such as infarction and villous ischemia. Results: Compared wi th 23 fetuses with nonischemic placentas, 24 growth-retarded fetuses w hose placentas showed ischemic lesions were more frequently delivered preterm (P < .001) and by cesarean for fetal distress (P < .01), and t hey also had lower mean pH, higher carbon dioxide pressure, and lower oxygen pressure values (P < .05). Compared with the fetal umbilical an d middle cerebral artery resistance indexes, the uterine artery resist ance index showed the highest sensitivity (91.7%), specificity (78.3%) , and positive predictive value (81.5%) for detecting placental ischem ic changes. Linear discriminative analysis also showed that the uterin e artery resistance index had the strongest correlation (P < .00001) w ith the placental ischemic changes. Conclusion: Ischemia of the placen ta is associated with an adverse pregnancy outcome in growth-retarded fetuses. The placental ischemic changes can be detected using Doppler flow velocimetry. Measurement of the uterine artery resistance index m ight be useful for determining the clinical management of growth-retar ded fetuses.