Ultrasound evaluation of amniotic fluid: outcome of pregnancies with severe oligohydramnios.

We studied a group of 247 patients out of 7725 patients who had an ultrasonic examination between 32 and 36 weeks gestation and were found to have oligohydramnios (amniotic fluid volume (AFV) less than or equal to 2.0 cm). We compared the features of labor and mode of delivery and perinatal outcome in this group with that of a normal control group of 247 patients who also had an ultrasonic examination between 32 and 36 weeks gestation and were found to have normal AFV (greater than 2.0 to less than 8.0 cm). The incidence of induction of labor, of elective cesarean section, of preterm delivery (less than 37 weeks' gestation) was significantly higher in the oligohydramnios group (study group) as compared with the incidence in the control group (P less than 0.05). The incidence of fetal distress in antenatal and intrapartum period, pH (less than or equal to 7.2), of low Apgar score (0-5), of intrauterine growth retardation (IUGR) (less than tenth centile) infants, of major fetal anomaly and perinatal mortality rate (PNMR) are significantly higher in the oligohydramnios group as compared with the incidence and PNMR in the normal control group (P less than 0.05). The ultrasonic finding of oligohydramnios should alert the clinician regarding the possibility of problems in labor and perinatal period.