A Chinese woman who spent five weeks in intensive care with H7N9 bird flu has given birth to a girl in what was described as a "miracle" first, state media said Friday.

Qiu Yan, 25, was five months pregnant when she was diagnosed with the virus in April, early in China's human outbreak of the disease.

She was in a "very serious condition" and underwent antibiotic, antiviral and hormone treatments, along with daily X-rays, during her therapy, the Global Times cited doctors as saying.

Qiu, from Zhenjiang in the eastern province of Jiangsu, is the world's first H7N9 survivor to give birth, the paper said.

"Her lung was severely infected and she needed a respirator to breathe because she was suffering from respiratory failure," it quoted Qiu's doctor Sun Lizhou as saying.

Qiu was discharged from intensive care in May but stayed in hospital until she delivered the baby -- a 3.3-kilogram (7.3-pound), 50-centimetre (1.6-feet) girl -- on Wednesday.

"It was a miracle," Sun said according to the paper.

The first human cases of the H7N9 virus were reported in late March and it had infected 132 people in mainland China, killing 43 by the end of June, according to official data.

Experts fear the possibility of the virus mutating into a form easily transmissible between humans, with the potential to trigger a pandemic.

Both Qiu and her baby were in stable condition but the child will have to be checked regularly for any possible effects of the virus, Sun added, according to the report.