Hong Kong: Hong Kong's public hospitals are struggling to cope up as 40,000 women a year from China cross the border to give birth in the wealthy city, a minister said.

Health Secretary York Chow said the number of mainland Chinese women giving birth in the city had risen from a few hundred six years ago to nearly half Hong Kong's 88,000 births in 2010.

"It really puts pressure on our obstetrics services and neonatal intensive care units and even maybe paediatric services," Chow said.

"This is a real problem we need to tackle," he said. "... Our basic principle is we have to give priority to local mothers."

Chow did not outline any specific measures to tackle the influx but was expected to meet hospital officials and doctors to discuss the issue, the newspaper said.

Heavily pregnant women from China have flooded over the border to give birth in Hong Kong since cross-border travel restrictions were substantially eased in 2003.

Babies born in Hong Kong are entitled to residency along with free education and health care in the former British colony, which remains substantially wealthier than neighbouring southern China.

Maternity fees for mainland Chinese women have been increased to around $5,000 per birth to try to reduce the influx, but the move has proved to be little of a deterrent.

Hong Kong reverted to China sovereignty in 1997 but has a separate financial and judicial system and maintains border controls with mainland China. China's one-child policy does not apply to Hong Kong.