Question: Patient is 17 weeks and has a “subchorionic hemorrhage.” Do we use O20.8? Our EHR system maps it to O41.8X2. What should we do? Indiana subscriber Answer: You should report O41.8X20 (Other specified disorders of amniotic fluid and membranes, second trimester, not applicable or unspecified) for a singleton pregnancy. A subchorionic hemorrhage (also called a subchorionic hematoma) is bleeding under one of the membranes (chorion) that surrounds the fetus. It is a common cause of bleeding in early pregnancy. As it is an issue with the membranes, this is why you should use O41.8x20.