Decreased amniotic fluid index in term pregnancy. Clinical significance.

In a study of 331 term pregnancies a four-quadrant technique was used to obtain amniotic fluid index measurements, and the results were compared with the current widely used single-pocket measurement. In contrast to the "2-cm rule," the amniotic fluid index measurements consistently demonstrated higher sensitivity in predicting poor fetal outcome with no decrease in specificity. It was noted that pregnancies with an index of < or = 8 cm showed higher incidences of meconium staining, cesarean delivery for fetal distress, abnormal fetal heart rate monitoring and Apgar scores of < or = 7 or less at one minute.