Oth dis of bld/bld-form org/immun mechnsm comp preg, 3rd tri

This code signifies the presence of a pre-existing or new-onset hematologic or immune system disorder that is adversely affecting a pregnant patient during her third trimester. This includes conditions such as anemia not specified as obstetric, thrombocytopenia, or autoimmune disorders, when they complicate the current pregnancy. The code indicates that the condition is impacting the pregnancy's course or management.

Use this code when documentation clearly states a blood, blood-forming organ, or immune system disorder is complicating a pregnancy that is currently in the third trimester. Examples include a pregnant patient with chronic idiopathic thrombocytopenic purpura experiencing a flare-up in the third trimester, or a patient with sickle cell anemia requiring specific management due to pregnancy-related exacerbations during the final trimester. The medical record must specify the trimester.

• Always sequence this code after the primary obstetric code (e.g., O09.- for supervision of high-risk pregnancy).
• Ensure the specific hematologic or immune condition is also coded to provide maximum specificity.
• Verify that the documentation explicitly states "third trimester" or provides the gestational age that falls within the third trimester.