Pre-existing secondary htn comp pregnancy, unsp trimester

This code signifies a patient who had secondary hypertension (high blood pressure caused by another underlying condition) prior to becoming pregnant, and this pre-existing condition is now complicating the current pregnancy. It indicates that the specific trimester of the pregnancy is not documented.

Use this code when documentation clearly states "pre-existing secondary hypertension complicating pregnancy" without specifying the trimester. This typically applies when the patient's medical history confirms secondary hypertension predating conception, and the current pregnancy is affected by this condition.

• Always seek to clarify the trimester if not documented, as more specific codes exist (O10.411, O10.412, O10.413).
• Distinguish carefully from essential (primary) hypertension complicating pregnancy (O10.01- series) or gestational hypertension (O13.- series).
• Code the underlying cause of the secondary hypertension (e.g., renal artery stenosis, Cushing's syndrome) as an additional diagnosis.