Unsp pre-existing htn comp pregnancy, first trimester

This code signifies a pregnant patient in her first trimester who has a pre-existing diagnosis of hypertension, but the specific type of hypertension (e.g., essential, secondary) is not documented. The hypertension is considered a complication of the current pregnancy.

Apply this code when a pregnant patient in her first trimester presents with a documented history of hypertension, and the medical record does not specify the type of hypertension. Documentation should clearly indicate the pre-existing nature of the hypertension and the trimester of pregnancy.

• Always sequence this code as a primary diagnosis when the hypertension is the focus of the encounter, followed by codes for the specific type of hypertension if known.
• Avoid using this code if the hypertension is gestational (new onset during pregnancy) or if the type of pre-existing hypertension is clearly documented (e.g., essential hypertension).
• Ensure the medical record explicitly states "first trimester" or provides sufficient information (e.g., LMP, EDD) to determine the first trimester for accurate code assignment.