Conjoined twins born with two heads and one body die aged less than a week-old

A baby born with two heads and one body in Mexico has garnered global attention after a short clip of it being held by doctors went viral.

Both heads of the conjoined twins can be seen alert and crying as they take their first impressions of the world at the maternity ward of a hospital in Ciudad Juarez, Chihuahua. They are thought to have been born with separate brains and shared internal organs.

The clip was reportedly filmed and uploaded onto social media by a family member on 6 January. The family were said to be expecting the arrival of conjoined twins following prenatal scans, but they have not spoken publicly about the birth. The sex of the twins is unknown.

On 10 January it was then reported that the twins died before doctors were able to perform any of the necessary operations on them. The mother is reported to be in good physical health.

Conjoined, or "Siamese", twins are identical twins which join in the foetus. They occur in approximately one in every 180,000 births, although they are reportedly more common in Africa and south-east Asia. Half are born still and another third day within a day. Female twins are more likely to survive than males.

Scientific opinion is divided as to whether the phenomenon arises as a result of a fertilized egg partially splitting or completely splitting before re-fusing with bridging stem cells.