When Peng Ankang was born prematurely in Hunan province in June, weighing just 800g, doctors didn't know if they could save him.
The baby's skin was purple and red and he was born after his mother experienced massive internal bleeding in the 25th week of pregnancy.
But after four months' treatment at a hospital in Loudi, the infant, whose name literally means "safe and healthy", has gained weight and is ready to be taken home on Sunday.
"The baby survived many crises in breathing, infection, bleeding, anaemia and body temperature," said Yi Junbo, director of the Maternity and Child Health Care Hospital in Loudi's Louxing district. "It's a miracle that he has grown into a healthy infant."
Yi Saijun, a doctor at the hospital, said: "I've never seen a baby so small. We didn't know if we could save him or not, but we decided to make our best effort.
The baby was accompanied by medical workers 24 hours a day."
The hospital said the boy now weighs 3kg and has developed well. It has waived some medical fees because of the family's financial situation.
Some people told the baby's parents, Li Xiongyan and Peng Hailong, before he was sent to the maternity hospital for treatment that they feared the couple would lose their child.
Li, the mother, said: "He looked so fragile, even smaller than my palm He's my flesh and blood. How could I give him up?"
Li, 19, and her 23-year-old husband left their hometown to earn money several days after the baby was born in a remote mountainous village in Xinhua county, Hunan.
The baby's grandparents sold pigs, cattle and all the family's expensive belongings to raise money for his treatment.
Peng Heping, the boy's grandfather, is virtually blind, while his wife has been taking pills for years to treat a serious disease. The infant's father is the family's only breadwinner.
Li hurried home after holding the baby for the first time when she was told by the hospital that her son could be discharged.
Residents in the couple's hometown are donating money to the family, and Peng and his wife are also seeking help from the local government.