Conjoined twin pregnancy, second trimester

This code signifies a pregnancy involving conjoined twins, specifically identified during the second trimester. Conjoined twins are a rare form of monozygotic twins where the fetuses are physically joined and share organs or body structures. The second trimester typically spans from week 13 to week 27 of gestation.

Apply this code when documentation clearly indicates a diagnosis of conjoined twin pregnancy and the gestational age falls within the second trimester. This diagnosis is typically established through prenatal imaging, such as ultrasound or MRI, confirming the fusion of two fetuses. The physician's notes should explicitly state "conjoined twins" and the gestational age or trimester.

• Ensure the documentation specifies "conjoined" twins, not just multiple gestations.
• Verify the gestational age or trimester is explicitly stated as the second trimester.
• Do not confuse with codes for other types of multiple gestations (e.g., O30.00x for twin pregnancy, unspecified).