Other specified abnormalities of chorion and amnion affecting fetus or newborn

This code signifies a diagnosed abnormality of the chorion or amnion that is not otherwise specified or classified, and which has an observable impact on the developing fetus or the newborn. These are conditions affecting the fetal membranes that are distinct from infections, premature rupture, or oligohydramnios/polyhydramnios.

Use this code when documentation specifies a particular, but less common, structural or functional anomaly of the chorion or amnion, such as chorioamniotic separation without premature rupture, or amniotic band syndrome affecting the fetus. The medical record must clearly state the specific abnormality and its documented effect on the fetus or newborn.

• Ensure the documentation explicitly links the chorionic/amniotic abnormality to an effect on the fetus or newborn.
• Do not use this code for conditions like oligohydramnios (658.0x) or polyhydramnios (657.0x), which have their own specific codes.
• Always sequence this code after the primary obstetric or perinatal condition if it is a contributing factor rather than the primary diagnosis.