Premature baby 'Tom Thumb' born at 25 weeks weighing half a pound survives

German doctors have revealed photographs of the smallest premature baby boy to have survived against incredible odds after being born at 25 weeks weighing just over half a pound.

A boy weighing only 275 grams after being born at University Hospital Goettingen in Germany is the world's lightest ever to have survived a premature birth

The baby, who doctors dubbed "Tom Thumb" was less than the length of a sheet of A-4 paper and weighed a fraction over 9.7 ounces (275 grams) when he was born by Caesarean section 15 weeks prematurely at the University of Medicine at Göttingen in western Germany in June 2009.

For 24 hours a day, the child was in an incubator and hooked up to feeding tubes, breathing tubes, a heart monitor, a catheter and a plethora of electronic devices to monitor every vital sign as he faced risks of cerebral haemorrhage or organ failure.

In December, the baby was finally pronounced "stable" after achieving a weight of 8.2lbs - considered an average birth weight in Germany.

Now, nine months after his birth, doctors have allowed the unnamed boy's parents to take him to the family home in Eighsfeld, central Germany, after ruling that he is strong enough to survive.

Officials from Göttingen hospital said that, having checked all available records of premature births worldwide, they were unable to find a viable birth of a boy at a lower weight. Three girls - including one born in the US at just 244 grams - had survived lower birth weights. The smallest boy previously recorded weighed 10.4 ounces.

Dr Stephan Seeliger, an expert on premature babies, said: "I spoke to the parents about the birth beforehand - whether we should go for it or not. In the end, I said: 'Good thing we did it!'"