[Histologic placenta findings in prolonged pregnancy: correlation of placental retarded maturation, fetal outcome and Doppler sonographic findings in the umbilical artery].

In 253 postterm pregnancies we investigated the correlation between retarded placental maturation, mode of delivery and fetal outcome and tried to answer the question, whether it is possible to estimate placental risk antenatal with pulsed doppler ultrasound of an umbilical artery. Villus maturation was determined by the criteria of Becker and the results were classified into 3 groups: Normal maturity, regionally or disseminated retarded maturation. In the latter group we found the highest rate of cesarean sections for fetal distress and a high neonatal morbidity. The birth weight was lower compared to the cases with normal placental maturity. As an index of placental resistance we determined the (A-B)/A-quotient of an umbilical artery with pulsed doppler ultrasound. The Resistance-Index was increased when the placental maturation was retarded. In 60% of cases with pathological umbilical artery flow velocity waveforms we found disseminated retarded placental maturation, whereas this occurred only in 6% of cases with normal flow.