Prognostic value of cardiotocography in pregnancy with pathologic Doppler findings

Abstract

Absent (absent-EDF) or reversed (RF) end-diastolic flow in Doppler velocimetry in the umbilical artery and fetal aorta indicates highly disturbed fetoplacental perfusion, which often occurs early in pregnancy. Perinatal mortality and morbidity is very high. In this situation it is not clear how long pregnancy can be continued to achieve better conditions for the preterm fetus. This study was performed to investigate the value of fetal heart rate recordings (FHR) in patients with absent EDF or RF as a parameter to determine the optimum time of delivery. 25 pregnancies with absent (n = 21) or reversed end-diastolic velocity (n = 4) were analysed. Gestational age was between 24 and 34 weeks. 17 children showed compensatory dilatation of the middle cerebral artery (68%). 15 (60%) were growth retarded, 8 of them below the 3% percentile, while 3 had normal weight. Maximum time interval until delivery was 18 days, median was 2 days. Five children died before, 2 during delivery. As none died after delivery, perinatal mortality was 28%. 4 of the survivers (22%) showed arterial acidosis. Only three children had completely normal fetal heart rate recordings on the day of diagnosis of absent EDF or RF. All others showed at least suspicious FHR (according to Hammacher), 8 of them (32%) even pathological FHR, including all children who died later. Early suspicious changes in FHR were the reduction in frequency and amplitude of oscillation, while decelerations occurred later. Additional unfavourable parameters in FHR were roundings of the oscillatory inversions as well as missing reactivity to fetal movements. Fetal heart rate monitoring is a reliable tool for determination of the optimum time of delivery in children with absent EDF or RF. The decision has to be made in relation to the gestational age. If possible, the fetus should be born before FHR becomes pathological. In this manner perinatal mortality and morbidity should be kept at a low level even in high-risk patients with absent EDF or RF.