Cutthroat competition for maternity beds in Hong Kong has pushed mainland mothers to make bookings even before they know if they have a viable pregnancy.
An increasing number also now rely on a quick blood test that can give a confirmation of pregnancy at four weeks, a week earlier than the usual urine test.
Some mothers have lost the HK$10,000 deposits they paid to secure a place at private hospitals because of miscarriages, which carry a 10 to 15 per cent risk in the first three months of pregnancy.
Dr Ares Leung Kwok-ling, deputy medical director of the Union Hospital, said the 'super-early birds' had emerged since April, when the government set a quota for mainlanders giving birth, then said this year's quota had been filled.
The cap was brought in to relieve the stress on obstetric and neonatal services.
'Those mothers come to us even before they can produce an ultrasound scan showing a viable foetus,' Leung said. 'This is something we have never seen in the past.'
He said the hospital would reserve a bed for the mothers and ask them to return in a month to produce ultrasound proof of a live fetus. 'We don't ask mothers to pay until we make sure it is a live pregnancy,' he added.