Maternal care for oth rhesus isoimmun, first trimester, unsp

This code signifies a pregnancy complicated by maternal care for rhesus isoimmunization, specifically when the type of isoimmunization is not Rh(D) and the pregnancy is in the first trimester. Rhesus isoimmunization occurs when an Rh-negative mother is exposed to Rh-positive fetal blood, leading to antibody production that can affect subsequent Rh-positive pregnancies.

Apply this code when documentation indicates maternal care for a rhesus isoimmunization other than Rh(D) (e.g., anti-c, anti-E) during the first trimester. This code is appropriate when the specific type of isoimmunization is identified as non-D, or if the documentation is insufficient to specify the type of rhesus isoimmunization.

• Ensure documentation clearly specifies "first trimester" and "other rhesus isoimmunization" or "unspecified rhesus isoimmunization."
• Do not use this code for Rh(D) isoimmunization; refer to the O36.01- series for those cases.
• Sequence this code as a primary diagnosis when the isoimmunization is the focus of the encounter, followed by codes for any associated conditions or complications.