The baby's leg at the time of birth is compared to a forefinger in this photo. [Photo provided by Southwest Hospital in Chongqing]

Xiaomi’s feet were only half of the size of an adult’s thumb when she was born at 24 weeks at Southwest Hospital in Chongqing on March 30, tipping the scale at just 585 grams.

Her chances of survival were very slim.

But after three months of treatment, the baby was finally discharged from the Intensive Care Unit to the normal ward this week, weighing nearly two kilograms, making her one of the smallest surviving babies in the world.

Her mother Chen Xia，31，and father Cao Lanwei，37，used Assisted Reproductive Technology at the same hospital. Chen’s water broke much earlier than expected. She was sent to the hospital and delivered the baby by herself.

“The baby was so tiny, as big as a medium-sized water bottle,” recalled Yan Ling, the pediatric head nurse.

“She couldn’t breathe by herself and her skin was transparent, as thin as a piece of paper.”

So the medical staff gave the baby a nickname: Xiaomi, which means “a grain of rice” in Chinese.

“I am so afraid of hurting her when taking care of my baby,” the mother said. “She is still so fragile.”

The father was confident his daughter can grow healthy after the early struggles.

The smallest surviving baby ever is believed to be Emilia Grabarczyk. She was born in Witten, Germany in 2015, weighing only 0.22 kg.