Question: There are different families of O codes for hemorrhage (we are comfortable using O26.85x1,2,3,9 (Spotting complicating pregnancy)). What is the subtle/fundamental difference between the following codes (our EHR - IMO does not differentiate between the two families very well)? If these are not classified elsewhere and in early pregnancy, what is the difference? Kansas Subscriber Answer: The O20 code category is used only for any bleeding that occurs before the completion of 20 weeks gestation. Threatened abortion refers the presence of bleeding with a closed cervix and a fetal heartbeat. Possible causes of bleeding during the first trimester include: Ectopic and molar pregnancies have their own codes so you would not use O20 if the cause of the bleeding was confirmed. The O46 code category is used only for bleeding in the antepartum period after 20 completed weeks of gestation. Placenta previa and abruption are the most likely causes, but they have their own codes and so the O46 codes would not be reported. Two other causes would be due to coagulation disease in the mother or afibrinogenemia, but an “other” code is provided to cover any other known reason. These “other” reasons can include in the second and third trimesters: Some of these conditions have their own codes, but if the source of bleeding has not been confirmed, the “other” code is appropriate to use.