A UK woman who was left reeling as a teen after being told she has two vaginas has beaten the odds and given birth to four children, including a pair of "miracle twins".

Plagued with painful periods as a teen, now 34-year-old Lauren Cotter says she thought she had polycystic ovary syndrome and went to get an ultrasound at age 16.

The scan revealed she actually had uterus didelphys, where a woman is born with two uteruses, two cervixes and, in her case, two vaginas.

"Up until the ultrasound, there were no signs that I was any different to anyone else," Cotter told The Mirror.

She had laser surgery a few months after her diagnoses, to divide the wall between her two vaginas, allowing her to enjoy a normal sex life.

She met future husband Ben a year later, and the pair were married in 2012.

Cotter says she was warned that the reduced size of her wombs and cervix might make carrying and delivering children very difficult.

But she went on to defy predictions, becoming pregnant with first daughter Amelie, now five, within a month of trying.

"We decided to give it a go, and just see what happened. We knew it might be a bumpy road and tried not to get our hopes up too much," she says.

"My obstetrician was quite honest with me and explained that, as I have two cervixes, it physically isn't possible for me to fully dilate enough for the baby to pass through.

"Therefore, I'd have to have an early delivery via C-section."

Her first child was born smoothly via C-section, and 18 months later she fell pregnant with her second, who was also delivered by C-section.

After Harvey was born, she was fitted with a contraceptive implant. But remarkably, three weeks after it was implanted she fell pregnant with twins. "Shocked doesn't even begin to cover it," Cotter says.

"My doctor was very honest and said he couldn't know how the pregnancy was going to play out."

But "miracle" Twins Maya and Evie were born via C-section last year, completing their family of four.

According to the World Health Organisation, the condition affects around one in 3000 women and occurs when the uterus fails to fuse properly during development in the womb.

Newshub.