The size of a mobile phone: Kimberley Mueller weighed just over 10 ounces when she was born in Hanover, Germany - making her the world's smallest surviving baby

She was was born 15 weeks premature and weighing ten and a half ounces, was just 10.2 inches long and weighed little more than a packet of butter when she arrived in the 25th week of her mother’s pregnancy. At this age mostly the survival rate is 1 in 1000s.

She was placed in an incubator for warmth, given a respirator to help her breathe and fed through a drip. Later she was also given a cocktail of drugs to boost an immune system that was barely formed.

At three months, she faced a major setback, when doctors feared she could be blind. But laser treatment corrected the problem. Her progress was underlined when she arrived home weighing five and a half pounds and measuring 17 inches. During the coming weeks she was continued to be fed artificially and needed to have oxygen as her lungs kept developing.

Current World Record

The world’s smallest known surviving baby was Rumaisa Rahman who weighed just 8.6 ounces when she was born in Chicago in 2004.