Infections of kidney in pregnancy, unspecified trimester

This code signifies a urinary tract infection specifically affecting the kidney (pyelonephritis) that occurs during pregnancy, where the specific trimester of the pregnancy is not documented. It indicates an infectious process within the renal parenchyma or collecting system in a pregnant patient.

Use this code when the physician's documentation clearly states "pyelonephritis in pregnancy" or "kidney infection in pregnancy," and there is no mention of the trimester (e.g., first, second, or third). This code is appropriate when the infection is confirmed, and the pregnancy status is known, but the timing within the pregnancy is unspecified.

• Always attempt to clarify the trimester from the provider if possible to use a more specific code (O23.01-O23.03).
• Do not use this code if the infection is limited to the bladder (cystitis) or urethra; refer to other O23 subcategories for those conditions.
• Sequence this code as the principal diagnosis if the kidney infection is the primary reason for the encounter, followed by codes for any associated organisms if identified.