Oligohydramnios

When the amount of amniotic fluid is 300ml, it is called oligohydramnios. This is a traditional concept, but it is difficult to accurately estimate the total amount of amniotic fluid regardless of vaginal delivery or cesarean delivery. In recent years, due to the application of imaging, especially the application of obstetric B-ultrasound technology, the diagnosis of oligohydramnios becomes more accurate, and the unified diagnostic standards have gradually been used clinically. The criteria for B-mode diagnosis of oligohydramnios is 5cm amniotic fluid index (AFI) or 2cm maximum amniotic fluid depth. In the past, the incidence of oligohydramnios was very low at only 1: 4000. In recent years, due to the improvement and popularity of prenatal monitoring of high-risk pregnancy and B-ultrasound technology, the incidence of oligohydramnios has increased. The incidence of oligohydramnios has been as high as 5% in some reports.