RELATIONSHIP BETWEEN THE FETAL HEART-RATE PATTERN AND PERINATAL-MORTALITY IN FETUSES WITH ABSENT END-DIASTOLIC VELOCITIES OF THE UMBILICAL ARTERY - A CASE-CONTROLLED STUDY

Fetal decompensation is usually diagnosed by the onset of late deceler ations and decreased fetal heart rate (FHR) variability and is associa ted with fetal hypoxemia and acidemia and has a high perinatal mortali ty. Objective analysis of the FHR pattern can be performed using the F ischer score and a score of less than 6 correlates with fetal decompen sation. Fetuses with absent end-diastolic velocities (AEDV) of the umb ilical artery have severe placental disease and coupled with this a hi gh perinatal mortality and morbidity. Importantly, AEDV is usually obs erved before the occurrence of fetal decompensation. In fetuses with A EDV, delivery before decompensation may improve the perinatal mortalit y and morbidity. To test this hypothesis, the perinatal outcome of fet uses with AEDV delivered before decompensation (Fischer score of 6 or more), were compared with similar fetuses delivered after decompensati on (Fischer score of less than 6). All FHR pattern records of fetuses who had AEDV with a birthweight greater than 750 g and a gestational a ge of 28 weeks or more were evaluated using Fischer's score by a singl e observer unaware of the perinatal outcome. Fifty-seven fetuses quali fied for the study and 17 of these babies subsequently died. The babie s who died had significantly lower mean Fischer scores during the prec eding 6 hours before delivery (5.9 +/- 1.8 SD) than the survivors (7.7 1.9; p <0.05), but also had lower birthweights and gestational ages. To obviate this effect, babies with a Fischer score of less than 6 at 6 hours before delivery (group 1) were matched to within 3 days gestat ional age and 10% birthweight with those with a Fischer score of 6 or more at 6 hours before delivery (group 2), Nineteen pairs were obtaine d. There were no differences in perinatal mortality and morbidity betw een the groups, although the surviving babies in group 1 spent signifi cantly less time in the hospital (p <0.02). Therefore, waiting until a decompensation, as is evident from a low Fisher score, develops does not adversely affect the prognosis of the fetus.