A Canadian woman who gave birth to a baby girl on board a plane from Calgary to Tokyo on Mother's Day (May 10) had no idea she was pregnant.
It was an event the baby's father, Mr Wesley Branch, described as "completely unexpected".
According to media reports, the woman, identified as 23-year-old Ada Guan, did not know she was 37 weeks along when she gave birth after going into labour over the Pacific Ocean. Guan and Branch had been dating for a year.
Guan started having stomach pains about two hours into the flight, her boyfriend's mother, Sandra Branch, told Global News.
"She didn't know what was happening to her," said Mrs Branch.
Because of the discomfort, Guan was moved into business class, and there happened to be three doctors aboard the flight who came to her aid after the air crew paged for volunteers.
Wesley Branch told Global News: "She told me, 'Something fell out of me'"
"I lifted up her pants, and I saw a head, and then I heard, 'Wah.'
"I thought, 'Oh, my God, I think we have a kid,' " he said.
According to Global News, Guan had taken a pregnancy test a few months ago, which came back negative. They thought she had just put on a little weight. A recent trip to the doctor also did not detect the baby.
The Air Canada plane from Calgary bound for Narita landed 30 minutes ahead of schedule after being bumped up the queue by air traffic controllers. The plane was given priority to land at Narita Airport, just outside the Japanese capital, AFP reported.
"I couldn't imagine. This happened completely unexpectedly," Branch had told Japanese television after the plane landed.
According to Calgary News, passengers had no idea what had happened until the captain informed them that there was a new passenger on board.
"Everyone was clapping their hands," a woman passenger told one television programme. "She's such a cute baby with big eyes."
The new mum was seen emerging from the plane in a wheelchair, while her partner carried his daughter in his arms.
Mother and baby were taken to hospital, where they remained overnight.
The couple named the baby Chloe, according to media reports.
Air Canada allows women with a normal pregnancy and no previous history of premature labour to travel up to and including their 36th week, reported AFP.