Thromboembolism in pregnancy, first trimester

This code signifies the occurrence of a blood clot that has traveled from its original site and lodged in a blood vessel, causing an obstruction, specifically during the first trimester of a pregnancy. This condition can manifest as deep vein thrombosis (DVT), pulmonary embolism (PE), or other forms of thromboembolic events.

Apply this code when a pregnant patient in her first trimester is diagnosed with any form of thromboembolism. Documentation should clearly state the type of thromboembolic event and confirm the gestational age or trimester of pregnancy at the time of diagnosis.

• Ensure documentation explicitly states "first trimester" for accurate coding; otherwise, a different trimester-specific code or unspecified trimester code would be appropriate.
• Always code the specific type of thromboembolism (e.g., DVT, PE) as a secondary diagnosis if known, in addition to this code.
• Do not confuse with codes for pre-existing thrombophilia or a history of thromboembolism without an active event during the current pregnancy.