Cerebroplacental ratio in prediction of adverse perinatal outcome and fetal heart rate disturbances in uncomplicated pregnancy at 40 weeks and beyond.

INTRODUCTION: The aim of the study was to determine the usefulness of Doppler velocimetry, based on cerebroplacental ratio (C/U) evaluation, in predicting intrapartum fetal heart rate abnormalities and adverse neonatal outcome in uncomplicated pregnancies at 40 weeks and beyond.

MATERIAL AND METHODS: One hundred and forty-eight women in uncomplicated pregnancies, between 40 and 42 completed weeks, were divided into control and study groups: with the absence (n = 79) and with the presence of a fetal brain-sparing effect (n = 69), respectively. Pulsatility and resistance indices in the middle cerebral, the umbilical artery and the C/U ratio were evaluated daily by Doppler ultrasonography. C/U < 1.1 was reported as suggestive of a brain-sparing effect. Abnormal flow indices were analyzed and compared to adverse pregnancy and neonatal outcome determinants.

RESULTS: In the abnormal C/U group the abnormal CTG records were significantly more frequently observed (62.3%) than in normal C/U group (19.0%) (p = 0.0001). The comparison of selected Doppler indices revealed that C/U showed the highest sensitivity in prediction of both the intrapartum abnormal FHR (74.1%) and the adverse neonatal outcome (87.8%).

CONCLUSIONS: The C/U index shows the highest sensitivity in prediction of FHR abnormalities and adverse neonatal outcome in uncomplicated pregnancies at 40 weeks and beyond. The C/U index is useful in clinical practice in antenatal monitoring of these women in order to select those at high risk of intra- and postpartum complications.