23 weeks amniotic fluid index how many mm normal

At 23 weeks of pregnancy, the amniotic fluid index is about 12.4-14.7cm. If the amniotic fluid index is 18-24cm, the amniotic fluid volume is 800-1200ml, which is normal. It belongs to polyhydramnios, and more than 24cm belongs to polyhydramnios. The amniotic fluid index is less than 8cm for oligohydramnios, and less than 5 cm belongs to oligohydramnios. Polyhydramnios or oligohydramnios are abnormal phenomena.