Family heartbreak prompted a couple from Radlett to raise almost £20,000 for Watford Hospital’s maternity unit.
Adrian and Sarah Sarosi's baby daughter died just seven months after she was born in May 2011.
Since then they have completed various challenges including the London Marathon and a 165km ride uphill through the Alps, and have raised £17,000 of their £20,000 target.
Sarah Sarosi said: "On May 11, 2011, my baby daughter Louisa was born sleeping at Watford hospital. At seven months, her heart stopped, and we will never know why.
"In May 2012, a very healthy Amelie was born to join her brother Henry who is nearly five years old. Our family is now complete.
"We competed these challenges in order to give something back, after the fantastic care and reassurance we received during this difficult time.
"We hope to raise enough money to buy a special care incubator, to help save lives for Watford Hospital, which has a very special place in my heart."
Sarah took part in the 2014 London Marathon and Adrian is cycled in the La Marmotte race - a 165km ride uphill through the Alps which takes place at the same time as the Tour de France.
Adrian started training in the winter to prepare for the climb. He said: "It was a brutal experience.
"It pushed me to the very limits of my capabilities. More than 1,000 of the starters failed to complete the course and I went past several ambulances on the way as many people weren’t as lucky as me.
"I’m very happy just to say that I made it around the course.
"It took me just over nine hours in the saddle to get around and unsurprisingly I felt rather sore and tired at the end.
"But knowing people have given so much to help me and my wife raise money for families going through so much more pain helped inspire me to get round."
Marmotte race is one of the hardest events in the French Alps, climbing about 5,200m or 17,000 ft - the equivalent of cycling from London to Nottingham, and the elevation is the equivalent of going from sea level to base camp of Everest.
Adrian added: "We’d like to thank everyone who has already donated. I am so pleased that we can give something back."
Frances Jones, head of midwifery at Watford Hospital, said: "We are thrilled that the Sarosi family is choosing to fundraise for us and we hope that we can look forward to seeing Amelie and Henry back here with Sarah and Adrian after the success of their fundraising as we would like to say thank you personally."
To donate to the hospital visit www.justgiving.com/teams/sarahadrian2014