Circumvallate placenta, second trimester

This code describes a condition where the fetal membranes (chorion and amnion) fold back on themselves around the placenta's periphery, forming a thick, opaque ring. This abnormal placental morphology can lead to reduced placental surface area for nutrient exchange and increased risk of complications.

Use this code when documentation explicitly states a diagnosis of circumvallate placenta identified during the second trimester of pregnancy. This diagnosis is typically made via ultrasound imaging. Supporting documentation should include imaging reports and physician notes confirming the placental anomaly and gestational age.

• Ensure the documentation specifies "circumvallate" and not "circummarginate" placenta, as these are distinct conditions.
• Verify the gestational age (second trimester) is clearly documented to support the specificity of this code.
• Code any associated maternal or fetal complications separately, such as preterm labor or fetal growth restriction.