Oth comp specific to multiple gest, second tri, fetus 1

This code identifies any complication unique to a multiple gestation pregnancy, occurring in the second trimester, and specifically affecting the first fetus. These complications are distinct from those that can occur in singleton pregnancies and are directly attributable to the presence of multiple fetuses.

Apply this code when documentation clearly indicates a specific complication related to a multiple gestation, such as twin-to-twin transfusion syndrome (TTTS) affecting fetus 1, or selective intrauterine growth restriction (sIUGR) of fetus 1, diagnosed during the second trimester. The medical record must specify the affected fetus (fetus 1) and the trimester of diagnosis or manifestation.

• Always sequence this code after the primary multiple gestation code (e.g., O30.-).
• Ensure the documentation explicitly identifies "fetus 1" as the affected fetus.
• Do not use this code for complications common to all pregnancies, even if occurring in a multiple gestation; use the appropriate O-code for the specific complication.