A baby has died after being born prematurely on a Cathay Pacific flight from Hong Kong to New York in a medical emergency that forced the plane, with 279 people on board, to divert to Japan.
The women, understood to have been in the later stages of her pregnancy but medically cleared to fly, went into labour some hours after the Boeing 777-300 took off from Hong Kong on Sunday afternoon.
Flight attendants rushed to the woman's aid while the captain diverted the plane to Tokyo, where emergency services were put on standby.
The woman and her baby were rushed to hospital on arrival at Narita Airport shortly after 10.30pm local time on Sunday. But sadly the infant did not survive.
Most passengers on board flight CX840 were unaware of the drama unfolding as cabin crew took the woman to a screened off area of the plane when she went into labour.
One passenger sent a message to a friend in Hong Kong shortly after the plane touched down in Tokyo.
She said she was unaware what had happened but had been told by crew that there was a passenger who "requires emergency support".
Some 20 minutes later, passengers were told that the woman had delivered a baby on board and that for security reasons they would have to stay overnight in Tokyo.
The passengers were put up in a Tokyo hotel and given meal vouchers. The flight departed for New York yesterday afternoon and was due to arrive there early this morning Hong Kong time - some 16 hours behind schedule.
Cabin crew are understood to be deeply upset over the incident but received praise from colleagues in Hong Kong.
"They were absolutely brilliant and did everything they could in very difficult and distressing circumstances," one colleague said. "It was just a terribly unfortunate thing to happen."
Cathay Pacific requires any passenger who is more than 28 weeks pregnant to obtain a medical certificate from their doctor to say that they are fit to travel.
The airline accepts passengers with uncomplicated multiple pregnancies up to 32 weeks into the pregnancy, and passengers with uncomplicated single pregnancies up to 36 weeks.
A Cathay Pacific spokeswoman declined to give an update on the woman's health. For privacy reasons no details were provided on her nationality, the sex of the infant or how many weeks pregnant the woman was when she boarded the flight.
A Cathay statement said: "Cathay Pacific's flight CX840, which departed from Hong Kong to New York at 4:22pm Hong Kong time on March 23, was diverted to Tokyo for a passenger to receive urgent medical care.
"The flight landed at Tokyo at 10.33pm local time and the passenger was sent to the local hospital for treatment, accompanied by our staff in Japan.
"As a result of the diversion … Cathay Pacific arranged overnight hotel accommodation and meal vouchers for the passengers. The flight has since resumed its journey to New York from 12:47pm local time on Monday."