Hannah Green's 30th birthday is a day she will never forget but not for the reasons you might expect. At 20 weeks pregnant, it was also the day Hannah, now 31, discovered her unborn daughter Lola had a congenital heart disease and would need open heart surgery as soon as she was born. With no history of the condition in the family the unexpected news left Hannah and her partner Gerard Bradley, 30, from Gosport, Hampshire, devastated, and Hannah vowed to do everything she could to ensure her daughter had the best start in life. Scroll down for video . Hannah Green with daughter Lola, now a happy and healthy eight months old . Hannah said: 'It was my routine 20-week scan and they couldn't see the valve coming off the left hand side of the baby's heart. 'None of this affected the baby while it was inside me but once the baby was delivered they wouldn't be able to get enough oxygen.' Hannah and Gerard's baby had transposition of the great arteries, a rare heart defect in which the two main arteries leaving the heart are reversed. Because of the shock diagnosis the couple decided to find out the sex of their unborn baby, which they had planned to keep a surprise. 'I felt like we needed to know her sex. I needed to feel something positive and connect with her. We didn't need any more surprises,' first time mum said. The diagnosis meant that Lola would need open heart surgery to switch the arteries back to their correct position as soon as she was born. Lola had open heart surgery when she was just ten days old in an eight-hour operation to swap arteries . Newborn Lola with proud parents Hannah and dad Gerard Bradley, a tattoo artist . 'It's so easy to take it for granted when you have a healthy baby. When you find out there's a problem with your baby that will require medical intervention you want to do anything you can to make it better.' So when Hannah attended London ExCel's Baby Show in February 2014 and came across stem cell banking company Precious Cells, she realised the procedure could prove priceless. Stem cells are found in the cord blood that remains in the placenta and umbilical cord, which are usually thrown away, after a baby is born. The stem cells are an exact DNA match to the baby and can help cure many life threatening diseases, such as leukaemia and sickle cell disease. Although stem cell banking is popular in America there are currently only four NHS hospitals in the UK offering the service. New parents – including Sky Sports presenter Natalie Pinkham who gave birth to her first child Wilfred in January - are using private stem cell banking companies instead. Hannah said: 'We were going to look for a crib and a pram and came away with information about stem cell banking.' Hannah feels comforted by knowing her daughter's precious stem cells will be there for her until she's 30 . The family poses for a snap, with Lola, who wears a pacemaker to regulate her heart, grinning at the camera . 'There are so many different things that can be done with stem cells. Doctors are creating better and new ways of doing things all the time, and we realised this could help our baby when she's older. It could also protect any future children we have.' But with a price tag of more than £2,000 the procedure was way out of Hannah and tattoo artist Gerard's price range. Luckily for Hannah Precious Cells was running a competition offering parents-to-be the chance to win free banking by explaining what the prize would mean to their family on the company's Facebook page. So Hannah – who until then had never won anything in her life - relayed her story and was stunned when she was chosen as the winner. The couple were given a box containing a special bag in which the cord blood could be stored, and the number of a phlebotomist who would come to the hospital and harvest the blood as soon as Lola was delivered. 'We had to call the number as soon as I went into labour and keep them updated on progress,' said Hannah, who was two weeks overdue when she finally went into labour in June last year. But because Lola's heart rate kept dropping she was born by emergency caesarean at Princess Anne Hospital in Southampton after a 36-hour labour, weighing a healthy 7lb 2oz. 'The phlebotomist was in the delivery room with us and she collected the cord blood and placenta straight away. She went into a separate room, took everything she needed and put it into a special bag. Then I was given the box back with the bag inside, and we had to call a courier to come and collect it.' Hannah Green says of Lola: 'We don't know what the future holds for us and the stem cells could help her heart condition in the future' Hannah Green had her daughter's stem cells harvested through Precious Cells . The courier arrived within hours of Lola's birth to collect the stem cells, which have now been cryogenically frozen by Precious Cells at their bio bank in London for 30 years. 'There are all sorts of certificates and insurance policies in case something happens to the storage facility or the company goes out of business,' says Hannah. Lola was immediately transferred to Southampton General Hospital where she underwent full open heart surgery in an eight-hour operation to swap the arteries in her heart when she was ten days old. 'It was a very traumatic, stressful and emotional time,' Hannah said. 'I wouldn't wish it on my worst enemy.' The surgery was a success and 10 days later Lola was fitted with a pacemaker to regulate her heart beat. At four weeks old Hannah and Gerard were finally able to take their daughter home, and although she will require life-long care she is now a happy and healthy eight-month-old baby. 'Babies who have undergone heart surgery can never have a normal heart again. They have a repaired heart,' said Hannah. 'We don't know what the future holds for us and the stem cells could help her heart condition in the future.' 'Sometimes I forget we have the stem cells banked, and then I remember and feel relief. It's an insurance policy for the future, just in case. If we don't end up using it I will find out whether we can donate it.' Sky Sport presenter Natalie Pinkham used a private stem cell banking company after having her first baby Wilfred in January .
Hannah Green's daughter  Lola was born with congenital heart disease . Mum from Gosport had blood from Lola's cord  harvested at birth . Her stem cells have been cryogenically frozen for 30 years .