When I worked for an operator here in Canada, we would advise the personal attendant accompanying the incubator that should the need arise to evacuate the aircraft, the infant should removed and the incubator left behind. The same procedure was used for passengers being transported on stretchers - remove the passenger and leave the stretcher in an evacuation.
Here is some Canadian guidance related to the installation and restraint of incubators and stretchers when carried on board a scheduled passenger aircraft, rather than a dedicated air ambulance:
Carriage of Incubators and Stretchers