Superfetation: Medical phenomenon sees Brisbane woman falls pregnant twice in 10 days

A rare medical phenomenon has seen a Brisbane mother conceive two baby girls 10 days apart.

‘Hole in one!’: Woman falls pregnant twice in 10 days

‘Hole in one!’: Woman falls pregnant twice in 10 days

Incredibly, Kate and Peter Hill only had sex once, but in a medical rarity known as ‘superfetation’, it is possible to fall pregnant while already expecting.

The couple were struggling to conceive after Mrs Hill was diagnosed with polycystic ovarian syndrome in 2006, a hormonal condition that left her unable to ovulate.

Charlotte and Olivia Hill were conceived 10 days apart. Image: Today Tonight

She underwent hormone treatment to spectacular results, falling pregnant not once, but twice.

As a conception oddity, superfetation is so rare there are only 10 medically documented cases of it in the world.

The non-identical twins - Charlotte and Olivia – baffled doctors and rewrote Australian medical history in the process.

Kate and Peter Hill were having problems conceiving, before undergoing hormone treatment. Image: Today Tonight

“We actually did not realise how special that (form of conception) was until they were born,” Mrs Hill told Today Tonight.

“What makes this case even more rare, is that my husband and I only had intercourse one time – his sperm stayed alive for 10 days to fertilise the second egg released.”

Mrs Hill explained that women did not usually ovulate once they fell pregnant - but she did.


Commenting on the rare conception, Mr Hill joked: “Hole in one, maybe.”

After their birth the girls measured very differently in size, weight and gestational development.

Now 10 months old, they also have different blood types.

Charlotte and Olivia are now 10 months old, but are very different in size and weight. Image: Today Tonight

“Superfetation is so rare that I could not find any literature in the medical review websites at all,” said Mrs Hill’s obstetrician, Dr Brad Armstrong from Greenslopes Private Hospital in Brisbane.

Dr Armstrong had to use Google to learn more about the medical phenomenon, with the Brisbane doctor becoming one of the few medical practitioners in the world to have dealt with superfetation.

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