Ventilation is a life saving procedure where a patient has a tube down the throat to breathe and a machine (ventilator) is used for the patient to help him/her breathe. Now, getting to your question: No, God willing, you never have to be on a ventilator. The Covid vaccine is absolutely recommended when women are trying to get pregnant, during pregnancy, and breastfeeding. There is enough data to support that now, thanks to all the pregnant women who got vaccinated over the last year. If you get the Covid vaccine, the chances that you will be on a ventilator is very low.
Take care and get vaccinated!!

Thanks for your question. I presume you mean placed on a ventilator in an ICU. All patients with a history of COVID need to be vaccinated, because it has been established that for a significant percentage, the immunity from the infection itself is inadequate for future protection. The vaccine should be given about 90 days (or more) after the original onset of the infection. Pregnancy is not a reason to demur on this decision, and the vaccine is safe in pregnancy, according to all studies so far on the mothers and babies.