ABSTRACT
Objective: Chronic Abruption Oligohydramnios Sequence (CAOS) is known as a disease with a poor perinatal prognosis characterized by placental marginal hematoma and genital bleeding, associated with fetal growth restriction, hemorrhagic amniotic fluid, oligohydramnios and chronic lung disease in the newborn. We reviewed the placental pathology of five cases diagnosed as CAOS without genital bleeding. Method(s): Pregnant women with CAOS without genital bleeding between April 2020 and July 2022 were identified. Five of these cases were clinically suspected as CAOS. Therefore, we evaluate the presence of hemorrhagic amniotic fluid and/or posterior placental hematoma by MRI;one case could not perform MRI because of COVID-19 infection. Placentas were examined histopathological and reviewed for the four Amsterdam classification groups, presence of diffuse chorioamniotic hemosiderosis (DCH), and other special findings. Result(s): The median age of the patients was 31 years and the median number of weeks of delivery was 24 weeks, including 2 cases of artificial abortion, 1 case of vaginal delivery, and 2 cases of cesarean section. The main complaints were FGR in 2 cases, amniotic fluid depletion in 2 cases, and suspected fetal congenital anomaly in 1 case. In histopathologic examination, 4 cases show DCH, 3 cases show maternal vascular marperfusion, and all cases had Acute chorioamnionitis. Conclusion(s): Four of the five patients had DCH, which suggest that the chorion and amnion are exposed to hematoma over a long period of time. This finding provides the basis for a final diagnosis in cases of clinically suspected CAOS. Our cases suggested that CAOS may be established before the appearance of genital hemorrhage. MRI or other tests should be performed aggressively in cases of clinically suspected CAOS without genital hemorrhage, and the patient should be strictly managed. Copyright © 2022