Thromboembolism in pregnancy, third trimester

This diagnosis code signifies the occurrence of a blood clot (thrombus) that has broken loose and traveled through the bloodstream (embolism) in a pregnant patient during her third trimester. This condition can manifest as deep vein thrombosis (DVT) or pulmonary embolism (PE), posing significant risks to both mother and fetus.

Apply this code when documentation clearly indicates a diagnosis of thromboembolism, such as DVT or PE, occurring in a pregnant patient who is beyond 28 weeks gestation. Supporting documentation should include physician notes detailing the diagnosis, trimester of pregnancy, and any associated symptoms or diagnostic findings.

• Always sequence this code after the primary obstetric code (e.g., O09.- for supervision of high-risk pregnancy).
• Specify the type of thromboembolism with an additional code (e.g., I82.4- for acute embolism and thrombosis of deep veins of lower extremity).
• Ensure the medical record explicitly states "third trimester" or provides gestational age indicating the third trimester.