Maternal care for oth isoimmun, third trimester, fetus 2

This code signifies specialized maternal care provided during the third trimester of pregnancy due to isoimmunization affecting the second fetus. Isoimmunization occurs when the mother's immune system produces antibodies against fetal red blood cell antigens, potentially leading to hemolytic disease of the fetus and newborn. This specific code indicates that the isoimmunization is not Rh-related, but rather due to other blood group incompatibilities.

Apply this code when documentation clearly indicates maternal care for isoimmunization (other than Rh) in the third trimester, and the affected fetus is specifically identified as the second fetus in a multiple gestation. This code requires documentation of the specific trimester and the affected fetus number.

• Ensure documentation specifies "other isoimmunization" to differentiate from Rh isoimmunization.
• Verify the pregnancy is in the third trimester and the affected fetus is clearly identified as "fetus 2."
• Do not confuse with codes for Rh isoimmunization (O36.0-) or isoimmunization affecting other fetuses.