Rosie and Ruby Formosa were born joined at the abdomen and sharing part of the intestine.
The twins, now 12 weeks old, were operated on at London’s Great Ormond Street Hospital the day after they were born on 27 July.
Their mother Angela, from Bexleyheath in south-east London, said the “smiling bubbly babies” were doing well.
The twins needed an emergency operation to separate them.
Mrs Formosa, 32, said finding out the twins were joined had been a shock after her “textbook” pregnancy with first daughter Lily, now aged five.The twins are now putting on weight and starting to smile, their mother said
“At an early pregnancy scan they said the twins looked very close together so I went to King’s College for another scan,” she said.
“Between 16 and 20 weeks we found out that they were joined – I didn’t know what to think, I was shocked and I felt sad.
“We didn’t know what to expect until they were born – the doctors could not tell where they were connected.
“They decided to deliver them early at 34 weeks.”
He said the girls had been joined by the abdomen at the level of the umbilicus.
“The operation to separate the twins had to be performed as an emergency because of an intestinal blockage,” he said.
“We are delighted with the outcome of the operation.
“The babies will need further treatment in the future, but we expect that they will both be able to lead happy and normal lives.”
Mrs Formosa said she and husband Daniel, 36, a taxi driver, were happy and relieved to have the girls at home.
“They are really well, they are putting on weight,” she said.
“They are normal bubbly babies who are starting to smile and cry when they want something.”
She added she was incredibly grateful to the hospital’s staff.
“What they have done for my two girls is amazing. When I was pregnant they were saying that the survival chances were quite low.
“For them to have been operated on and doing so well – it is amazing.”