Marathon Runner Gives Birth To Surprise Baby A woman goes to hospital for what she thought was a training-related back injury and finds out she is actually pregnant.

The surprise baby has been named Mira, short for Miracle 

By Sky News US Team

A woman training to run a half-marathon has given birth to a baby she did not know she was carrying.

Trish Staine, of Duluth, Minnesota, went into hospital on Monday after feeling back pains that she thought were caused by her intense workout schedule.

Instead, doctors delivered a six-pound baby girl.

Named Mira - short for Miracle - the baby was born about five weeks early and appears to be healthy aside from a case of low blood sugar, WDIO-TV reported.

Mrs Staine, 33, says she had no idea she was pregnant. When doctors detected a foetal heartbeat, she told them it was impossible.

"I definitely thought I was done having kids," she joked. Staine and her husband, John, have a daughter, 7, and a son, 11. She's also stepmother to John's three boys, aged 17, 19 and 20.

Mrs Staine insists she did not gain weight, has maintained a normal menstrual cycle, and that her husband, John, has had a vasectomy.

She told WDIO-TV she has always been sceptical about women who say they were surprised when they gave birth, but now says: "I'm a believer."