LONDON - The first day of kindergarten is a big day for all youngsters, but for a set of formerly conjoined twins it's a milestone.
Rosie and Ruby Formosa, 4, were born joined at the abdomen and sharing part of their intestines.
They were delivered by caesarean section at 34 weeks gestation.
After undergoing surgery as infants, the pair beat the odds to survive.
According to the University of Maryland Medical Center, the condition occurs in one in 200,000 live births.
The girls, who live in Bexleyheath in southeast London, recently posed in a photo of their school uniforms.
Angela Formosa, their mother, told BBC News that her daughters were "very excited" to start school.
"When I was pregnant I didn't think I'd ever see their first day at school, so it is really amazing, and all thanks really," Formosa told BBC News.
Professor Paolo De Coppi, consultant pediatric surgeon at the hospital, expressed his excitement for the twins.
"It's always a joy to witness patients' progress and to hear that they are reaching new milestones-- this makes the job we do all the more rewarding," he told BBC News.