A doctor is running his 11th marathon in a bid to raise funds for the Oxford baby unit he has developed over the past 30 years.

Prof Chris Redman, 59, will raise money for a £100,000 ultrasound scanner for the Silver Star Baby Unit, at the John Radcliffe Women's Centre, by taking part in Sunday's London Marathon.

The consultant in obstetric medicine will be accompanied by six other runners - five of whom have children who were saved by doctors and nurses at the department, which looks after sick babies and their mothers.

Product management director Stuart Reynolds, 39, of Swindon, wanted to help boost funds for the Silver Star unit because his son Paul, seven, was born there. He hopes to raise £5,000.

Mr Reynolds's wife, Lynn, had a series of miscarriages before Prof Redman and his team stepped in to help. He said: "We had almost given up hope when we were told about Prof Redman at the Silver Star Clinic. They gave us so much help before Paul's birth that my wife and I just can't thank them enough.

"Running through the rain at 9pm at night you often think it's not worth it, but coming home to see my little boy asleep in his bed reminds me of why I'm doing it."

Also running are Sean Ryan, Paul Staines, Steve Turner and Huw Warren and Women's Centre clinical lecturer Howard Cannatella.

Prof Redman said more than 5,000 families have received help at the unit and many of the babies are now grandparents themselves.

He said: "I think my last marathon is going to be harder than the first and certainly much slower. But keeping the unit at the forefront is too vital to resist the challenge."

Donations to the Silver Star Baby Unit should be sent to Dee Nudds, Nuffield Department of Obstetrics, John Radcliffe Hospital, Oxford, OX3 9DU.