Hong Kong says it will restrict the number of mainland Chinese women allowed to give birth in the city's hospitals which are struggling to cope with the tens of thousands who arrive each year.

The number of mainland women who opt to deliver across the border in the glitzy financial hub has been growing and reportedly accounted nearly half of Hong Kong's 88,000 births in 2010.

Hong Kong's government has come under pressure in recent weeks after doctors made a rare public call for a cap on the number of babies delivered in the city as resources for local mothers are stretched thin.

Mainland mothers are keen to give birth in Hong Kong, a city of seven million that maintains a semi-autonomous status within China, because it will entitle their child to right of abode and education.

Following the pressure, Secretary for Food and Health York Chow announced Wednesday the government would set a quota for mainland mothers based on available facilities, manpower and demand at the city's hospitals.

"I think there is a need to control the number of mainland pregnant women coming to Hong Kong," Chow said in a statement, adding the number of local mothers giving birth is expected to increase.

"The total number of deliveries in Hong Kong has to be set at a certain limit so that we can maintain the professional standards and also the quality of care," he added.

Chow said the government would finalise details in coming months, and that the new regulations would apply to eight public hospitals and 10 private hospitals with maternity units in the southern Chinese city.