Amniotic fluid index in the management of the postdates pregnancy.

This is a prospective evaluation of the relationship between the amniotic fluid index (AFI) and perinatal outcome in 55 postdates pregnancies. The gravid abdomen was divided into four quadrants, using real-time ultrasound with a 3.5 mHz transducer, the largest pocket of amniotic fluid in each quadrant was measured and their sum totalled to arrive at the amniotic fluid index. AFI in this study ranged from 2.8 cm to 22.6 cm. The mean for 41 weeks was 13.52 +/- 4.6 cm and for 42 weeks, 9.93 +/- 4.37 cm. Oligohydramnios was noted in four patients, AFI less than 5.3 cm. Two of these cases developed intrapartum foetal distress and had Caesarean Section. All four babies were admitted with meconium aspiration and one died from this complication.