When Karen Wood gave birth for the second time on February 18, 2009, her placenta did not come out.
She was taken straight into surgery to have it removed. Doctors thought they got it all, but they were wrong.
Five weeks later, after several hospital visits for infection and further surgery attempts to remove the rest of placenta, she was back in surgery again but something went wrong.
"A surgical instrument had broken through my uterus resulting in me hemorrhaging internally.
"They had to perform an emergency open hysterectomy. They estimated I lost about 3l of blood, an average women only has about 5 and a half litres of blood in their body."
She needed 14 units of red blood cells and plasma, some of which had to be flown in from Hamilton.
Each unit of blood contains about 300mls.
Her husband, Keith, was sitting in the waiting room and could see the helicopter arrive with the blood and knew something was very wrong.
Her new born son, Noah, was only five weeks old and his big brother, Lincoln, was two.
"It's hard to express in words how important how vital the 4per cent of people who donate blood are.
"My husband would have been on his own to raise two boys who would have never known their mum.
"How do you thank strangers for a gift like that?"
Mrs Wood had been a blood donor since she was 16.
"It just seemed a good thing to do."
She has also been working for the NZ Blood Service for the past ten years as a registered nurse.
"My job literally saved my life."
Mrs Wood said she still got emotional about the ordeal she went through.
"The surgeon said to me quite a few times, they almost lost me.
"I don't think people realise what they are doing when they are donating blood. They think its a nice thing to do. I don't think they realise how much of an impact it has on people.
"Especially now looking at the boys as they grow up, it's always in the back of your mind they could not have a mum. My husband could be doing it on his own which is pretty scary."
Her husband Keith had just given his 25th blood donation, he hates giving blood but knows first-hand how important it is.
Mrs Wood had O- blood which meant she could donate her blood to everybody else, but could only receive O- blood back in return.
"It's just being able to have it there in case it's needed. It's only a matter of time before you, or someone you know is going to need it."
Statistics show that less than 4 per cent of all possible donors in New Zealand actually roll their sleeves up and give each year.
Giving blood doesn't just benefit recipients. Regardless of who you are, donating blood offers many benefits for donors.
It lets you:
Help save the life of up to 3 people with a single donation of blood.
Make a difference in your community by helping others.
Develop a sense of commitment to and connection with your fellow Kiwis.
Be assured that adequate supplies of blood are available for you, as well as your family and others.