An investigation into stillbirth has found the parents of 2.6 million babies are suffering in silence each year because of slow progress in combating the problems related to delivering a stillborn baby.
It also highlighted wide gaps between the rich and poor, even in high-income countries.
The report published in the Lancet medical journal, was compiled by more than 200 authors, investigators and advisers from 43 countries, including Auckland University.
In New Zealand the rate of stillbirths, which is the number of babies that die after 20 weeks, is 2.3 per 1000 births according to figures in The Lancet.
Out of 186 countries New Zealand was ranked tenth for the fewest rate of stillbirths.
For the first time, researchers also looked at the traumatic, life-long consequences for families, and found over four million women suffered from symptoms of depression following stillbirth.
Auckland University's head of obstetrics and gynaecology, Professor Lesley McCowan contributed to the research.
Prof McCowan told Nine To Noon stillbirth was; "an enormous problem... it has a devastating impact on the families that are involved."
The problem was still far too common and had a huge impact on families, though New Zealand was one of a number of countries in the developed world where there had been a small reduction in stillbirths, Prof McCowan said.
"In New Zealand we're doing relatively well, we could still do better but our statistics at the moment, for example, are better than Australia, they're better than the UK, so we can be proud of those data," Prof McCowan said.
The significant reductions were for babies that died in labour.
The mother's sleeping position may influence stillbirth and that is an area that Prof. McCowan and her team have researched, publishing a paper on the subject in the British Medical Journal in 2009.
"And what we identified was that women who settled to sleep on their left side after 28 weeks of pregnancy had about half the risk of late stillbirth compared to women who went to sleep (in other positions), particularly on their back," Prof McCowan said.
Her team is working on a larger study to try to confirm those initial findings..
"And if they are confirmed, we may have a very simple message that may reduce the risk of still birth going forwards," she said.
The uterus of a woman in late pregnancy was quite large and if she lay flat on her back, the weight of the uterus could reduce the blood supply going through the major blood vessels in the abdomen, Prof McCowan said.
"And that can reduce the blood supply to the developing baby, whereas we know that women who sleep on their left side - from physiological studies that we're doing and from older work - that that tends to optimise the blood supply to the baby.
"So our hypothesis is that if you've got a vulnerable baby - and it's very difficult at present to identify a vulnerable baby - then the mother sleeping on her back might be the final step that leads to the loss of the baby," Prof McCowan said.
Many stillbirths involved smaller than normal babies too.
"That's another big problem, 30 to 40 percent of all stillborn infants are smaller than they should be, and that means they haven't been growing well in the womb - and that's usually because of placental problems," she said.
The New Zealand College of Obstetricians and Gynaecologists and other professional groups are working with the Ministry of Health to develop an educational package to help practitioners better recognise small babies before birth.
"Because at the moment, we only pick up about 25 percent of babies who are not growing well before they're born, and so this is currently a huge problem in antenatal care - and it's not just in New Zealand, it's globally," Prof McCowan said.
Despite well-developed antenatal scanning technology, detecting smaller babies in healthy women was an area which could still be much improved.
The weight of pregnant women was a third cornerstone of their research, with heavier mothers having a marked increased risk of stillbirth.
A paper in The Lancet showed that women who gained about 11kg from their first to their second pregnancy had a significantly increased risk of having a stillborn baby - or a baby that died after birth.
"Unfortunately most women gain more weight during pregnancy than is optimum for their health or their baby's health at present."
Listen to Professor Lesley McCowan on Nine To Noon