Forty years ago a small fridge in Glasgow held all the hope in the world.

It was 1978, and while it might have been fairly unremarkable to look at, inside it were rows of glass bottles, each one as precious as the lives they were there to help save.

It was Scotland's first milk bank, set up to provide for some of the country's tiniest and most vulnerable patients.

The women donating the milk were mothers themselves so they knew exactly what they were giving - not just a bottle, but a physical message of love and hope from one mother to another.

Today the milk bank has grown from that one fridge plugged into a wall in Glasgow, to 15 neonatal units now served across Scotland.

While the project may have grown, the message has remained the same - mothers helping mothers and tiny lives being saved.

"When I first started we were feeding 20 babies, now we're feeding well over 500 babies," says Donor Milk Bank Coordinator Debbie Barnett.

"I've got a great photograph of those early days. It was literally just a fridge or a freezer where mums would leave their extra milk."

The milk bank manages on just three full time staff and an incredible team of 10 volunteers who drive around the country collecting and making 'milk drops'.

"We collect milk from all over Scotland, it comes into Glasgow, gets tested and then sent out," explains Debbie.

"It's quite an operation in terms of coordination."

The milk bank provides screened pasteurised human milk to babies who have no or limited access to their own mothers milk, including babies who are often born prematurely.

Premature babies are born with immature intestines and immature immune systems, so they are often at greater risk of infection and Necrotising Enterocolitis, a potentially fatal gut condition.

Breast milk from a baby's own mother is always deemed the best nutrition but this may not always be available, especially in the first few days of life.

Donated human milk is the next best alternative.

"It's not just about the babies," says Debbie. "It's about taking the pressure off their mothers too and being able to support them."

Donors are screened and the milk heat treated before it is sent out.

All breast milk has bacteria in it, and in normal circumstances these are acceptable and actually helpful.

However, because donated milk is used to feed preterm and sick infants, the milk bank team try to ensure no unwanted bacteria are present.

Those donating their breast milk are screened in exactly the same way as blood donation.

To be a donor, your baby must be under six-months-old when you make your first donation. The team can also take stored milk that is less than 90-days-old. You can donate until your baby is between nine and ten-months-old.

"The thing I love most about my job is that I think we're making a huge difference," says Debbie. "We're really contributing to the health and well being of these very vulnerable infants and their mothers."

The team is celebrating two major birthdays this year - the 40th anniversary since that first fridge went into operation - and the five year anniversary since the group in its current form started operating.

It's hoping to have a celebration this summer to mark the occasion with the Glasgow Children's Hospital Charity, the main group which provided funding to make the project what it is today.

The team still has big plans for the future, with hopes for more staffing and an entry into the paperless world, bringing in scanners instead of paperwork to manage the milk drops.

Despite a tightly packed schedule, Debbie was happy to take a moment to send out a special message on mother's day to all the mothers in Scotland she and her team have recruited or have helped.

"It would be lovely to thank our all our donors, our volunteers, many of whom are mums," she says.

"You should all be proud of what you are doing - you are literally saving lives.

"And to anybody who has had a baby up to seven months, if you are interested in donating please get in touch.

"It really is a very valued service and you could be part of helping mothers and babies in Scotland."