Prenatal diagnosis and obstetric management.

Conjoined twins are rare, representing 1 in 50,000 to 1 in 200,000 live births, and the prognosis is generally poor. Accurate prenatal diagnosis by an experienced multidisciplinary team using a combination of imaging modalities allows parents to make fully informed choices. This may include termination of pregnancy, which is easier and safer at the earlier gestations at which diagnosis is now being made; continuing with the pregnancy but accepting that only palliative care is appropriate after birth; or planned intensive care and separation of the twins after birth. Delivery will invariably be by cesarean section in order to minimize the risk of peripartum harm to both mother and babies.