'It's really important': Kiwi mum's plea to pregnant women after losing baby in stillbirth

A mother of a little girl who died in the womb is urging pregnant mothers to listen to messages about sleeping on your side.

A new study from the University of Auckland has found that mums who sleep on their backs could harm their baby.

A pink teddy embroidered with a date is one way Tania Cornwall remembers her little girl whose heart stopped beating.

"She was stillborn at 31 weeks - it came as a tremendous shock to us."

Every year, 300 babies are stillborn in New Zealand.

Cornwall says it can be extremely hard to manage the emotions that come after a stillbirth.

"Guilt and blame can be the hard things to live with when a baby dies, because they're living with us - so we feel the things we do in our life [are] vital to them."

But Auckland researcher Lesley McCowan has found a simple switch of sleeping position can, in some cases, more than half the risk of stillbirths.

"Every life that could be saved is vitally important, because this is a tragic complication," she says.

The link was first made in New Zealand eight years ago, triggering several major studies around the world.

This final chapter is proving to be the strongest evidence yet that a mother's sleeping position can affect their baby.

When a mother lies on her back, the IVC - a major vein in her abdomen - gets squashed, reducing the flow of blood by 80 percent.

"Whilst a healthy baby can cope with these kinds of changes, a baby that's vulnerable for some other reason may not be able to," says McCowan.

It eliminates a risk, but doesn't prevent stillbirths altogether - pregnant women who are over 40, obese, smokers or have a baby that's growing poorly are still at risk of losing their baby.

Tania Cornwall is urging all expectant mums to pay attention to the study.

"Having that knowledge of things we can arm ourselves with and tools to help reduce our risk of stillbirth is really important."