Woman has sex once and gets pregnant twice, 10 days apart
An Australian woman has given birth to two babies, who were conceived 10 days apart despite only having sex once.
The BBC reports that Kate Hill was receiving hormone treatment after Polycystic ovary syndrome (PCOS) stopped her ovulating.
Normally, once an egg is fertilised a second egg is not produced but in this case a second egg was produced and incredibly it too was fertilised.
The phenomena, known as superfoetation, is so rare that there have only been 10 recorded cases in medical history.
The twins, Charlotte and Olivia, were different sizes, weights and at different stages of the gestational period when born 10 months ago.
Most twins happen after two eggs are released at once or if a fertilised egg splits in two.
Speaking on Australian TV Mrs Hill's husband Peter joked: "Hole in one, maybe."