Prediction of oligohydramnios in prolonged pregnancy

A decrease in amniotic fluid in prolonged pregnancy is associated with incr eased fetal morbidity. However, few investigations have been reported on th e prediction of this condition. Fetal renal arterial pulsatility index (PI) , hourly fetal urine production rate (HFUPR) and amniotic fluid index (AFI) at 39 weeks were studied in 51 singleton pregnancies with (n = 14) and wit hout oligohydramnios (AFI < 5, n = 37) in prolonged pregnancy. There was no difference in the average fetal renal arterial PI and HFUPR between the ol igohydramnios group and the normal group. However, the average AFI in the o ligohydramnios group was 7.5 +/- 0.9, which was lower than that in the norm al group (p < 0.05). We speculated that AFI value at 39 weeks is useful for predicting the incidence of oligohydramnios in prolonged pregnancy.