Maternal care for oth rhesus isoimmun, second tri, fetus 1

This code signifies a pregnancy complicated by maternal antibodies against fetal red blood cell antigens due to Rh incompatibility, specifically when the mother has developed antibodies to an Rh factor other than D. This condition is being managed during the second trimester of pregnancy and refers to the first fetus in a multiple gestation.

Use this code when documentation indicates maternal Rh isoimmunization (e.g., anti-c, anti-E, anti-Kell antibodies) affecting the fetus, excluding the more common anti-D isoimmunization. The patient must be in her second trimester of pregnancy, and this code is specifically for the first fetus in a multifetal pregnancy. Documentation should clearly state the type of Rh isoimmunization and the trimester.

• Ensure the documentation specifies "other" Rh isoimmunization, not anti-D, which has a separate code.
• Verify the trimester of pregnancy and the fetal number (e.g., fetus 1, fetus 2) are clearly documented.
• This code requires an additional code from category Z3A to specify the weeks of gestation.