World's smallest surviving boy goes home from hospital

The world’s smallest surviving baby boy has been taken home from hospital in Japan after a lengthy stay in intensive care.

The tiny boy weighed just 268 grams when he was born at Keio University hospital in Tokyo in August, Kyodo News reported.

The child’s mother had an emergency caesarean when she was 24 weeks pregnant, after it was deemed the baby was not growing and his life was in danger.

The baby was initially so small he could fit in both hands, the hospital said, but grew steadily and was eventually able to breastfeed.

At his release from hospital, he tipped the scales at 3.238kg, more than 12 times his birth weight.

According to the Tiniest Babies Registry website, the previous record for the smallest surviving boy was a child born in Germany in 2015 who weighed 274g.

The smallest baby to survive is a girl who was also born in Germany in 2015, weighing 252g.

For babies born weighting less than 300 grams the survival rate was low, especially for boys, doctor Takeshi Arimitsu told Kyodo News.

But babies born weighing than 1kg generally had a high survival rate of about 90 percent in Japan.

"I want people to know that babies can return home vigorous even if they are born small," he said.