Middlemore Hospital's earthquake safety called into question

Auckland's Middlemore Hospital could suffer major disruption as questions are asked over earthquake safety.

The hospital's Galbraith building, which houses the country's largest maternity unit, is understood to require major work to bring it up to standard - and even temporary closure of the maternity unit.

Alison Eddy from the NZ College of Midwives says a significant contingency plan will be needed.

"The volume of women using that service and the level of need is such that you couldn't simply close a service like that without having an alternative service for those women to use."

Prime Minister Jacinda Ardern has been reassured that people's safety has not been put at risk, but says they'll have to be mindful of natural disasters.

"Volcanic and ash loading tends to be on top of Aucklanders' mind... but that doesn't mean that we don't have earthquake standards that we have to comply with too."

While it's the Counties Manukau District Health Board's responsibility to manage seismic risk and the safety of staff and occupants, the Ministry of Health says it is engaging with the DHB.

The DHB is assessing to what extent the building is still safe to use and a board meeting will take place next week.