Ultrasonography in the antepartum diagnosis of conjoined twins. A report of two cases.

The advent of new and effective methods for the neonatal evaluation and treatment of conjoined twins has greatly increased the importance of prenatal diagnosis of this complication. Ultrasonography has become the method used most commonly to diagnose and evaluate multiple pregnancies. All ultrasonographers should be familiar with the signs associated with conjoined twins. We treated two patients in whom the antenatal diagnosis of conjoined twins was made by ultrasonography alone. One is the first reported case of the antenatal ultrasonographic diagnosis of conjoined twins in different presentations. The findings associated with conjoined twins are: (1) lack of a separating membrane, (2) inability to separate the fetal bodies, (3) presence of fetal anomalies, (4) identification of more than three vessels in a single umbilical cord, and (5) sonographic detection of any of the classic radiologic signs.