An amniotic fluid index of 68mm at 36 weeks is not normal. An amniotic fluid index less than or equal to 5cm during pregnancy is considered to have too little amniotic fluid, and those with an amniotic fluid index between 5-8cm have relatively low amniotic fluid, although there is no clinical diagnosis. So an amniotic fluid index of 68mm at 36 weeks is considered to have oligohydramnios. Amniotic fluid is dynamically balanced, if the ultrasound suggests that the amniotic fluid index is 6.8cm, you need to pay attention to the investigation of the reasons for the occurrence of low amniotic fluid, such as whether there is a premature rupture of the membranes, whether there is a combination of fetal anomalies, placental hypoplasia, diabetes mellitus, gestational hypertension, etc., and at the same time, dynamically monitor the changes in the amount of amniotic fluid. If the amniotic fluid index is 68mm on ultrasound, it is recommended to consult a specialist.