Claire Crowley, aged 35, and her husband Roger, 39, have been trying for a baby since they got married five years ago.
Since then they have gone through the trauma of two failed pregnancies – the second of which ended with Claire being rushed into theatre for emergency surgery.
Now the couple from Southey Hill, Parson Cross, have been offered fertility treatment to finally get them on the road to having a family.
But Claire’s doctors have told her she needs to shed a third of her 18 stone bodyweight to be eligible for IVF, and to give her a better chance of conceiving.
Claire, who sells cruise holidays for a living, has embraced the challenge and has already lost two stone, dropping to 16 stone 2lbs.
And she has turned her dieting into a fundraiser - with the aim of losing her first 28 pounds by January 28 tomorrow. Friends and family have been sponsoring her in aid of the Ectopic Pregnancy Trust.
Claire had already been through the agony of one miscarriage when she found out she was pregnant again in late 2008.
But when she went for a nine-week scan her doctors found something was wrong.
“When I had the scan they couldn’t see the foetus and thought it might be stuck in a fallopian tube,” Claire said.
“They admitted me to hospital and discovered I did have an ectopic pregnancy.
“I was taken down to surgery and then they said they might have to remove my womb.
“Luckily that didn’t happen, but my left fallopian tube was badly damaged and it had to be taken out.”
Claire was left grieving for her unborn baby - and struggling with the news she might not conceive naturally again.
“You don’t see it as just losing a foetus – you are grieving for a lost child,” she said.
“You have this pregnancy and this baby, and when it’s gone it is a real grieving process.”
Despite the heartache, Claire is looking to the future and is determined to lose weight so she can start the family.
“Being healthy and losing weight is a part of my lifestyle now,” Claire said.
“I started on my diet back in November and I decided to raise money, so I set myself the goal of losing 28 pounds by January 28.”
All the money she raises will go to the Ectopic Pregnancy Trust, which helped her through the trauma of her second failed pregnancy.
“The trust is brilliant. They give you support and you can talk to people who have gone through the same thing,” she said.
n Log on to uk.virginmoney giving.com/clairecrowleyfightingtheflab to donate.