Hayley Ross is due to give birth Jan. 5. She was asked to leave a hot yoga class at Yoga Shack in London because she's pregnant. (Supplied photo)

A London midwife is speaking out after being told she can't attend hot yoga classes at a popular studio because she's pregnant.

Hayley Ross had been going to her hot yoga class for nine weeks when she was told she couldn't continue.

She was told by an instructor her pregnancy might make others in the class uncomfortable, so she couldn't come back until after she gave birth. She was also told hot yoga wasn't safe for pregnant women.

"I was told I couldn't make my own decision. I felt horrified. I was a little in shock because I'd been practicing yoga there for so long. But they told me I couldn't continue," said Ross, who is due Jan. 5.

"She told me I was a distraction, that her other clients weren't happy about me being there. So that was it."

Ross is a London midwife who has delivered more than 1,000 babies in the 10 years she's been practicing.

She and a couple friends started going to hot yoga at Yoga Shack for a weekly get-together.

"I'm hoping that people are horrified that they're discriminating against a pregnant person. I am an experienced midwife," Ross said.

Ross was cleared by her own midwife to attend the hot yoga class.

"There are no randomized control trials about hot yoga in pregnancy. I've done a lot of research on the topic," she said.

Others might be anxious about pregnant yogi

But Yoga Shack owner Lisa Shackleton said that while the studio offers prenatal yoga, she won't allow pregnant women to take hot yoga because of studies she's read that say the classes can lead to complications.

The fact that Ross is a midwife, and has clearance from the midwife who will deliver her baby, doesn't sway Shackleton.

"For me, that is our policy. Your occupation doesn't determine how your unborn child can react to the heat," she said.

"Not only am I concerned about the health of her and her baby, but I'm also concerned about our staff teaching the class and other members in the class," Shackleton said. "There are other people who are worried for that person. It's a private journey on your mat but you're also in a room full of people. I don't want people anxious about whether or not she is going to faint."

Shackleton said she's done her own research and no longer allows pregnant women in hot yoga classes. Since the dispute with Ross she's made that clear on the Yoga Shack website.

"I told (Ross) that with time and reflection she might look back and see that I had the health and safety of her baby in mind," she said.

Feeling embarrassed, guilty

Another woman, pregnant at the time, said she was told to leave a hot yoga class at the Yoga Shack in 2015.

Vanessa Romphf was seven months when she ran a half marathon and then was kicked out of a hot yoga class at Yoga Shack in London. She was told others in the class weren't comfortable with her being there. (Supplied photo )

"I was about seven months pregnant and Lisa came up to me and said that she wasn't comfortable with having me in the class because I would make other people uncomfortable. I was shocked about that because I thought the philosophy of yoga was all about being yourself, in that moment," said Vanessa Romphf, who has since moved to Hamilton, is pregnant again and does hot yoga in a studio that sees no problem with pregnant women.

"I felt pretty discriminated against, embarrassed, guilty."

"I had just trained for a half marathon. I was seven months pregnant. She didn't bring up safety at all with me. I told her I would have my doctor or my midwife call and she said 'No.' If her emphasis was on safety I would have been more understanding. But it was all about how I would make other people feel uncomfortable."