What is the most common type of conjoined twin?: (A) Craniopagus, (B) Thoracopagus, (C) Ischiopagus, (D) Pygopagus
Answer is B. Conjoined twins or Siamese twins are monozygotic twins, formed when the twinning of the embryo occurs after 12 days of feilization. Thoracopagus- fusion of thorax (most common type) Xiphopagusoromphalopagus- fusion of anterior abdominal wal Pygopagus- posterior fusion Ischiopagus - caudal fusion Craniopagus- fusion of cranium Rachipagus- dorsal fusion 6