Women in labour at a UK hospital will not be given gas and air for pain relief, it has been announced.
William Harvey Hospital in Ashford, Kent, has banned the painkiller for two weeks because of ventilation issues in its labour rooms.
East Kent Hospitals Maternity said current levels of gas in the air "could affect the health of staff" over long periods.
It comes a month after a damning report into maternity services at East Kent Hospitals Trust found that up to 45 babies might have survived if they had received better care.
Gas and air (Entonox) is a common method of pain relief during labour and is a mixture of oxygen and nitrous oxide.
While it is safe for mother and baby, it could be harmful for doctors and nurses who are exposed to it over longer periods because of the hospital's ventilation issues.
In a statement, East Kent Hospitals University NHS Foundation Trust said: "We regret and are sorry to tell you that women in labour at our maternity department at William Harvey Hospital will not be able to access Entonox (gas and air) at the moment.
"Mums and babies are not at risk of harm. We expect to be able to use Entonox again within two weeks."
It is understood that new ventilation systems for the maternity unit have been ordered and the environment on the wards is being continually monitored.
The hospital says it will still be able to offer mothers every other method of pain relief.
Anyone who is due to give birth at the William Harvey Hospital in the coming weeks is advised to speak with their midwife about their options.
The decision to stop offering gas and air was criticised after the trust published its statement on Facebook.
One comment read: "Oh goodness, how heartbreaking for both families and the midwives working on the unit.
"How this was ever allowed to happen is beyond me, someone needs to be held accountable."
Last month, an independent report into maternity services at East Kent Hospitals University NHS Foundation Trust found that up to 45 babies would have most likely survived had they received better care. Babies died while others were left badly hurt as a result of catastrophic failings.
Mothers were also left injured and some died, the report found.
The inquiry looked at maternity care at the Queen Elizabeth The Queen Mother Hospital (QEQM) in Margate and the William Harvey Hospital between 2009 and 2020.