Conjoined twins are identified by specific terms. These terms describe the point of connection. Twins may be conjoined at the:
- Abdomen (omphalopagus).
- Chest (thoracopagus).
- Top of head down to the belly button, facing each other (cephalopagus).
- Head only (craniopagus).
- Pelvis, facing each other (ischipagus).
- Pelvis, side-to-side (parapagus).
- Rump-to-rump (pygopagus).
- Vertebral column (rachipagus).