[Clinical management of fetuses with diastolic zero or negative flow of the umbilical arteries: duration of clinical observation and fetal outcome].

40 fetuses with diastolic zero flow or diastolic reverse flow of the umbilical arteries were examined in a longitudinal analysis. While 35 fetuses had to be delivered by cesarean section, three fetuses showed intrauterine death which seemed to be inevitable, and two fetuses were delivered vaginally without signs of fetal distress. In one third of our study group the cesarean section was necessary immediately after admittance to the obstetrical ward. The remaining two thirds were clinically observed up to one or up to four weeks respectively. The shorter the interval between diagnosis of the zero flow and delivery the larger was the gestational age, the amount of severe fetal acidosis, and the number of emergency cesarean section. The clinically observed groups were delivered significantly earlier and fetal blood gases were normal. Only one case of emergency cesarean section was observed. The bad fetal outcome of fetuses with diastolic zero flow of the umbilical arteries is therefore caused by the hypoxia and asphyxia of the not hospitalized and clinically observed high risk pregnancies. The early diagnosis of this flow pattern and the immediate clinical admittance and surveillance with doppler flow measurements and CTG-monitoring including the oxytocin challenge test allows to reduce the amount of fetal acidosis by adequate timing of the delivery. Acute placental insufficiency in cases with diastolic zero or reverse flow commonly occurs before the 33. week of pregnancy.