McDonald's serves pregnant Canadian cleaning fluid latte

McDonald's has issued an apology after an expectant mother in Canada was served cleaning solution instead of the latte she ordered.

Sarah Douglas, who is eight months pregnant, asked for the coffee at a drive-thru in the province of Alberta last Sunday morning.

She took a sip a short while later only to discover the brownish liquid in her cup was not coffee and milk.

Ms Douglas pulled her car over and immediately spat out the substance.

She drove back to McDonald's and told one of the employees she wanted to speak to the supervisor, she told Lethbridge News Now.

"I showed him the coffee and he had asked if I wanted a new one, and I said, 'absolutely not, this is unacceptable,'" she told the news site.

The restaurant franchisee said in a statement he was sorry for the incident.

He explained that the machine had been cleaned as usual that morning but the milk supply line to the latte machine had not been disconnected from the cleaning solution while Ms Douglas' drink was prepared.

"We have taken immediate action to review the proper cleaning procedures with the team and have put additional signage up as an added reminder," said franchisee Dan Brown.

The pregnant mother of two told Global News that she feels fine but nonetheless visited her doctor as a precaution.