In a case that is almost unheard of in the medical community, a British mother has defied the odds of a one-in-200 million chance and gave birth to an identical set, or "tridentical," of triplets.

Experts say that while the chance of conceiving triplets from a natural pregnancy is about 4,000 to one, giving birth to an identical set of triplets is almost unheard of.

Thomas, Edward and Harry Chalwin, delivered in April by Cesarean section at 34 weeks weighing just 4lbs each, look so alike that their 33-year-old mother Claire paints their fingernails with different colors to tell them apart, according to The Sun.

"It was difficult in the early stages, which is why I came up with the color coding idea," she told the UK-based newspaper.

"I'd apply it once a week to ensure we always knew which was which. Now I have no problem telling them apart," she said.

All three boys had to wear gastric feedings tubes for the first three weeks of their after they were born at Stoke Mandeville Hospital, Buckinghamshire, on April 13. 

The trio, at nearly four months old, now weight at a healthy 12 pounds each.

The mother of the triplets Claire, a former nurse, and the father Paul, a recruitment consultant, really wanted a sibling for their now three-year-old son William after a Claire had a miscarriage last June.

Claire says that her trio of newborn sons is "a wonderful gift".

"They are a wonderful gift, I love them all and I am blessed," she said.