An Australian woman who was told she may never fall pregnant has given birth to twins conceived 10 days apart.
Kate Hill was receiving hormone treatment for polycystic ovary syndrome, a condition that left her unable to ovulate.
She conceived twins at different times despite only once having unprotected sex during that period.
A rare condition known as superfetation makes it possible to conceive for a second time when pregnant.
The twin girls, Charlotte and Olivia, were born 10 months ago with different size, weight and gestational development.
‘We actually did not realise how special that was until they were born,’ Hill told Australia's Seven Network.
Pregnancy normally stops the monthly cycle of ovulation but superfetation allows it to continue.
It is believed only 10 cases of the phenomenon have been documented across the world.
Speaking about the rare conception, Hill's husband Peter joked: ‘Hole in one, maybe.’
The couple's obstetrician Brad Armstrong said the condition was so rare he was forced to search for it online.
‘I could not find any literature in the medical review websites at all,’ he said.