Conjoined male twin delivered at University of Nigeria Teaching Hospital five days ago through caesarean section. Pictured on the resuscitator and radiant warmer as the doctors are working round the clock to keep them alive.

Their abdomen and thorax are fused. 2D Echo showed that they have separate heart. Abdominal scan also showed that they have different abdominal organs.

Doctors in the house, is there a possible cause to birth defects like this?