A Florida woman with a rare condition gave birth to a pair of twins from two separate uteruses last week, according to a press release from Morton Plant Hospital in Clearwater, Fla.

The woman, 24-year-old Andrea Barbosa, has a rare condition called uterus didelphys, or double uterus, which affects about one in every 2,000 women worldwide. She and her husband, Miguel Barbosa, welcomed their healthy fraternal twins, Nathan and Natalie, on Sept. 15.

I was shocked to learn I had a baby in each uterus, said Barbosa, who also has a two-year-old daughter. But my husband and I are just so happy that they are here and healthy.

There have only been about 100 known cases of women with a double uterus being pregnant in both uteruses at the same time. The condition -- which can cause infertility, miscarriage or premature birth for many women -- is extremely rare, with experts estimating that only about one in five million such pregnancies succeed.

In the four percent of women who have reproductive abnormalities, five percent have a double uterus. Of those, only about three percent are likely to conceive one child in each uterus while only one percent of those who do will carry the babies to term.

In 2009 another American woman, Sarah Reinfelder of Michigan, also defied the odds when she carried twin girls in both of her uteruses.

A double uterus develops in the female fetus before birth and occurs when the two tubes that normally fuse together to form the uterus fail to form, developing into two separate cavities.

Dr. Patricia St. John, who delivered Barbosa's twins, said her patient knew the risks involved in the unusual pregnancy.

Because we were aware of her condition, we were able to take special precautions to ensure that both mother and babies would be healthy, she said.