By Suranjana Tewari, Aug. 9: A baby thought to be the world's smallest at birth has been discharged from a Singapore hospital after 13 months of intensive treatment.

Kwek Yu Xuan was just 212g (7.47oz) - the weight of an apple - when she was born and measured 24cm long. She was delivered at just under 25 weeks - far short of the average 40.

The previous record-holder was a girl in the US who weighed 245g at birth in 2018 according to the University of Iowa's Tiniest Babies Registry.

Yu Xuan's mother gave birth to her by emergency C-section four months ahead of schedule after she was diagnosed with pre-eclampsia - dangerously high blood pressure that can damage vital organs and be fatal for both mother and baby.

Yu Xuan now weighs a much healthier 6.3kg (14 pounds).

The baby girl had a "limited chance of survival" according to Singapore's National University Hospital (NUH) where she was born.

"Against the odds, with health complications present at birth, she has inspired people around her with her perseverance and growth, which makes her an extraordinary "Covid-19" baby - a ray of hope amid turmoil," the hospital said in a statement.

Yu Xuan was born four months ahead of schedule by emergency C-section, KWEK FAMILY

During her time in hospital, Yu Xuan was given multiple kinds of treatment and relied on different kinds of machines to survive.

Doctors say her health and development progressed well under their care and she is now well enough to be discharged.

Yu Xuan still has chronic lung disease and will need help with her breathing at home. However, NUH doctors say she is expected to get better with time.

Her mother, Wong Mei Ling, told local media that Yu Xuan's birth and size came as a shock because her first child - a four-year-old boy - was delivered at term.

Yu Xuan's parents were able to pay for her long hospital stay through a crowdfunding campaign that raised S$366,884 ($270,601).