Ioan Gruffudd's pregnant wife Bianca Wallace has been left "unable to function" after struggling with intense morning sickness

In a video posted on Instagram, she was seen lying in bed as she told her followers: "I've thrown my back out so f****** bad vomiting, I can't function.

"I can't sleep, I'm in so much pain. I can't function. Really enjoying being pregnant."

She added in the caption: "Life lately ... Some real moments, because no one needs to be as shocked as I was to find out how fkd pregnancy actually is ... Weeks 6-13 were like some kind of torture I'll be happy to never experience again."

She added of her video from bed: "Slide #1: Vomited so aggressively that I threw my back out for 4 days."

Bianca added another picture of herself with a bowl of cornflakes and revealed it was one of the few food she could eat for much of the early stages of her pregnancy.

She wrote: "Cornflakes. One of the roughly two and a half things I could eat for a couple months."

Bianca - who suffers from autoimmune disease multiple sclerosis - went on to add: "I'm doing ok now! This is a PSA [public service announcement] for the first time newly pregnant Mamas or Mamas who are trying who, like me, were totally clueless that it can get wild, fkd, and pretty bloody insane (... and I've lived and coped with a very angry MS for 7 years and struggled terribly to cope with the first trimester!!).

"You're not crazy! More often than not it isn't just nausea and 'morning sickness.

"It IS s*** and rough and fkd and all of those things and it IS ok to be honest about it! I didn't know that everyone goes through a pretty horrid time until I started talking about it and hearing the same in response!

"I really wish I'd heard some pregnancy realness before my 6 weeks melt down feeling like I was crazy. So this is some of the realness that I wish I'd seen or heard before it all began!"

It is the first child for Bianca, while her actor husband Ioan is also dad to two daughters with his ex-wife Alice Evans.