NEW YORK (Reuters) - A woman from the South Dakota state in the United States felt pain in her abdomen and went to the hospital thinking she needed surgery to break up kidney stones, only to find out she was pregnant with triplets, including a boy, and was about to give birth.

"When I started to feel pain, I thought it was kidney stones," Danette Giltz told Kota TV. "I had never had such an experience before. I didn't know I was pregnant."

She carried out a biological analysis that learned that the source of the pain she felt was not gravel but the symptoms of childbirth.

The father of the children says he is still trying to understand what happened even after his wife and the three twins left the hospital, and that he is overwhelmed by emotions.