Births in New Zealand could be reduced by up to a third if mothers were non-smokers, not overweight and under the age of 35, health researchers say.
British medical journal The Lancet this week published a series of six papers on the subject of stillbirth internationally which researchers hope will lead to greater efforts to eliminate preventable stillbirths.
Speaking at a Tasmanian media conference this week, International Stillbirth Alliance Board member and Australian obstetrics and gynaecology Prof David Ellwood said about one in 130 births in Australia and New Zealand would result in a stillbirth - seven babies a day.
Many of them would be at the gestational age where survival, if they were born alive, was possible.
In 2009, 496 babies who had reached 20 weeks' gestation were stillborn in New Zealand.
Using the World Health Organisation definition of stillbirth, which uses the later 28 weeks' gestation, in 2009 New Zealand ranked 33rd out of 193 countries. Finland has the lowest rate.
Prof Ellwood said in high-income countries such as Australia and New Zealand, three significant risk factors contributed to the stillbirth rate.
Overweight mothers had about 12 % of stillbirths, mothers over the age of 35 had 11%, and smoking mothers had 6%.
Information from the Australian and New Zealand Stillbirth Alliance says 16% of women smoke during pregnancy in New Zealand.
New Zealand estimates were not given for alcohol consumption, but The Lancet research suggested about 50% of women in high-income countries drank alcohol in pregnancy, resulting in an estimated increase in the odds of stillbirth by 40%.
The alliance said while it was recognised many women might not be in a position, or want, to become pregnant younger, the best advice for those planning a pregnancy was to quit smoking and lose weight if necessary.
The alliance said the most common conditions of stillbirth in Australia and New Zealand were spontaneous preterm birth, often associated with infection, and congenital abnormalities.
In New Zealand, haemorrhage before birth occurred was also an important factor.
Researchers said stillbirth remained unexplained in many cases, but many were not comprehensively investigated and important causes could be missed. Researcher Philippa Middleton said it had been shown one of the reasons some stillbirths were not investigated was the difficulty clinicians had in broaching the topic of an investigation with the parents.
More training was needed in that area, she said.
The Lancet paper addressing the issue of stillbirth in high-income countries noted there had been a dramatic decline in stillbirths in the 1940s but this had slowed or stalled since.
It suggested parent organisations were powerful agents for change, as shown in the case of sudden infant death syndrome. They had an important part to play in raising awareness to help prevent stillbirth.
