Not even the doctors thought they could survive.
Now the 22-year-olds, who share one body fused at the torso, will be starring
in their own reality TV show chronicling their graduation from Bethel
University in Minnesota, their post-grad job search and their travels through
Europe with friends.
The girls first captivated the world in 1996 when they appeared on The Oprah Winfrey Show and the cover of Life Magazine.
Since then they have lived a quiet, normal life with their family in Minnesota, keeping away from the media spotlight until they agreed to appear on a documentary for TLC when they turned 16.
The broadcaster has now given them their own show called 'Abby and Brittany' which will premiere on August 28.
When the Hensel twins were born on March 7, 1990, in Minnesota in the United States, doctors warned their parents Patty, a registered nurse, and Mike, a carpenter and landscaper, that they were unlikely to survive the night.
The girls have two spines, two hearts, two oesophagi, two stomachs, three kidneys, two gall bladders, four lungs, one liver, one ribcage, a shared circulatory system and partially shared nervous systems
When growing up, they, like many twins, had very different personalities and tastes.
Abigail, the feisty, stubborn one, liked orange juice for breakfast, while Brittany, the joker of the family, would only touch milk.
They also stunned doctors with their astonishing co-ordination while playing the piano, with Abigail taking the right-hand parts and Brittany the left.
They enjoyed sports such as bowling, volleyball, cycling, softball and swimming.
And on their 16th birthday they passed their driving test, a mind-boggling feat of teamwork with each twin using one arm to control the steering wheel.
Speaking at the time, their mother Patty, a registered nurse, conceded that could have been a problem.
'I don't know what would happen if they got pulled over for speeding.
Would they each get a ticket or just Abby because it's her foot on the accelerator?'
The Daily Mail first introduced the Hensel twins 16 years ago, when they were six years old, and now their latest escapades show the dramatic progress they have made into early adulthood.
The Hensels are believed to be one of only a few sets of dicephalus twins in history to survive infancy, and when they turned 16, they allowed the cameras into their fiercely guarded private world to share this milestone in their lives.
Speaking back then, Brittany said: 'Believe me, we are totally different people.'
It has not been unknown, however, for the twins to go out in a specially made top with two different necklines - to reflect their unique tastes - and leggings with each leg a contrasting colour and a different shoe on each foot.
One set of twins in every 40,000 is born connected in some way to each other and only 1 per cent of those survive beyond the first year.
