[Evaluation of the usefulness and reference values for the amniotic fluid index in normal pregnancy between 30 and 42 weeks of gestation].

The four-quadrant sum of amniotic fluid pockets (amniotic fluid index) was studied prospectively in 130 normal pregnancies from 30 to 42 weeks. Statistical investigation were used to establish the mean, 95% confidence intervals and standard deviations for the AFI at each week of gestation. The AFI value decreased since 30 week, especially between 33 and 34 week and after 41 week. The AFI value < or = 5 represents oligohydramnios, the AFI value > or = 20 constitutes polyhydramnios.