Deformed foetus. Coloured X-ray of a foetus with multiple deformities. The development of the skull (upper centre) and the ribcage is incomplete, and the spine (centre left) is bent. The foetus could have been aborted or miscarried. Such deformities would result from environmental damage to the developing foetus. Viral infection of the mother and exposure to chemicals are among the causes of such deformities. Damage at a cellular level would disrupt the genetic instructions that prompt the embryonic tissues to develop into limbs, different tissues and organs. The resulting deformities will be more severe if the damage occurs early on in the pregnancy.