Placentitis, unspecified trimester, fetus 3

This code signifies inflammation of the placenta occurring at an unspecified point during gestation, specifically affecting the third fetus in a multiple gestation pregnancy. Placentitis can be caused by various infections (bacterial, viral, fungal) and may lead to adverse pregnancy outcomes.

Use this code when the medical record documents placentitis in a multifetal pregnancy, and the specific trimester of onset is not documented, but it is clearly identified as affecting the third fetus. Documentation should confirm the diagnosis of placentitis and the fetal order.

• Ensure the documentation explicitly identifies the affected fetus as "fetus 3" in a multiple gestation.
• If the trimester is known, a more specific O41.1- subcategory should be used.
• Code any underlying infectious agent (e.g., bacterial, viral) separately if identified.