London - Lying side by side with big, bright smiles, it’s hard to believe twins Carter and Grayson Swailes share a bond so close it almost killed them.
Mother Paula Wilkinson was warned her boys had a slim chance of survival after doctors found their umbilical cords had become entangled in "intricate knots" in the womb.
With every movement, the brothers risked cutting off their supply of oxygen and nutrients – and had to be delivered by emergency caesarean at just 29 weeks.
But the pair, who weighed little more than a bag of sugar each at birth, have thrived against the odds, celebrating their first birthday earlier this year.
Wilkinson, 36, who lives in Crewe with her partner, business analyst Leighton Swailes, 37, had been thrilled to discover that she was pregnant with twins after the birth of her first son Isaac two years ago.
But the couple’s joy soon turned to despair when a sonographer told them they would be having rare and risky monochorionic monoamniotic twins.
The "MoMo" condition, which means babies share the same amniotic sac and have separate umbilical cords, occurs in just one percent of twin pregnancies and has a 50 percent survival rate.
The close proximity of the cords poses a risk of complications such as entanglement or compression.
Wilkinson said: "I couldn’t believe it when I saw the twisted knot of their umbilical cords. They were literally plaited together. Those intricate knots had been killing my babies.
"We were told it meant that every time the babies moved, there was a chance their umbilical cords could get more and more tangled up. We had been so excited to hear I was pregnant with twins, now we were just terrified that they wouldn’t survive."
Wilkinson was warned one twin was not growing as quickly as the other and in January last year, when she was 29 weeks pregnant, the smaller twin’s heart rate began to drop.
"They had to get them out quickly to give them a chance of survival," she said. The boys spent their first month in hospital.
But more than a year on, the twins are happy and healthy – and although Grayson is still smaller of the two, Wilkinson says that even relatives struggle to tell them apart.
"They like to be together as much as possible and often they’re just one tangle of arms and legs – just like their cords were," she added.