Michelle Wright, aged 37, who works at City Hospital in Birmingham has tested positive for coronavirus.
Ms Wright, who is 29-weeks pregnant, is now being cared for at Russells Hall Hospital in Dudley.
The key worker has had to have steroid injections to mature her unborn child's lungs in case her condition deteriorates.
She recorded a video message from her hospital bed in the high dependency unit calling on people to take advice seriously and stay home and save lives.
Watch the BBC's video here:
Through her oxygen mask she said: "This virus is very unpredictable, I struggle too much to breathe on my own.
"I hope this is temporary and I just pray things start to improve, I've not got any worse in the last 24 hours but this virus does not discriminate.
"I'm not going to talk for long, but what I wanted to say was please, please listen to Government advice, social distancing, keep yourself and your families as safe as possible. If you can, stay in and save lives."
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The nurse's words were echoed by Toby Lewis, chief executive of the hospital trust which employs her, who also pleaded with people to stay home.
Michelle's sister Donna told the BBC today that her breathing is starting to improve.
Donna added: "She is still in high dependency and is being really well looked after. Despite Michelle struggling to breathe, all the signs are really positive that everything is fine, so that's brilliant."