A Hertsmere Jewish Primary School teacher is running her first charity race as a thank you to Great Ormond Street Hospital doctors and nurses who saved her son's life.

By taking part in next month's Adidas 5km Women's Challenge in Hyde Park, Sarah Jacobs hopes to raise at least £3,000 towards the hospital's new heart and lung centre, helping children like her son Eitan with major cardiac problems.

Two weeks after undergoing open-heart surgery at Great Ormond Street for the third time in his short life, two-year-old Eitan is back at the family home in Borehamwood and making good progress. Born with life-threatening heart defects, he underwent surgery to repair an aorta problem when he was just one week old.

"We have been to hell and back," Mrs Jacobs told the JC following Eitan's latest operation.

"At one point, his heartbeat appeared to have stopped. I slept on a chair by his bed for four nights and for nine days I didn't even get to see my other two children, seven-year-old Rafi, and Cobi, five. But the doctors and their teams were phenomenal and they pulled him through. I can't praise them highly enough."

Mrs Jacobs and her Dutch-born husband Danny wanted to express their gratitude in a meaningful way; hence her decision to do the Adidas run. She is already two-thirds of the way to her target figure.

As well as the hospital's help and support, the Jacobs family also received encouragement from friends and relations. Prayers for him were said by "all the pupils at Hertsmere Jewish Primary, plus the kids at Rosh Pinah and the Menorah Foundation School in Edgware, and even the children in an Amsterdam school to which my husband's family has links".

She described Eitan as "an amazing little boy - a real fighter. Despite all his problems, he has developed normally. Apart from being a little underweight, he s a typical two-year-old, attempting to imitate everything his older brothers do."

The Jacobs are Borehamwood and Elstree Synagogue members.