CDHB planning and funding general manager Carolyn Gullery said the site was still contaminated with asbestos, but the health board was looking at ways to manage it.
She said options for the site were being looked at, but there were no set time frames around the project.
There are currently 45 maternity beds at the Christchurch Women's Hospital maternity unit, and she said on average 30-40 women were admitted each day.
The CDHB also has a three-year contract with St George's Hospital to provide maternity services, which expires in 2019.
Across Canterbury, about 6000 babies are born each year.
There was currently enough capacity to meet the needs of all Canterbury women within the system, she said.
The Colombo St hospital was built in the 1950s, but demolished in 2008 after the current Christchurch Hospital facilities opened.
The future use of the land had not been decided when the building was demolished.