Rare identical triplets amongst quadruplets
21 August 2012 Last updated at 09:37 BST
Quadruplets who were all born on leap year day, 11 weeks early, are preparing to turn six months old.
Emma Robbins from Bristol gave birth to four boys by Caesarean section within six minutes of each other at St Michael's maternity hospital.
At their birth, two of the babies were believed to be identical - thought to be a one in a million chance. But doctors now believe that Joshua, Zachary and Rueben could be identical.
John Maguire reports.