Melbourne study finds pregnancy length depends on ethnicity

THE length of a healthy pregnancy differs for different ethnicities, a Melbourne study has found, with some pregnant women more at risk of stillbirth than others.

A FINDING that says the length of a healthy pregnancy differs for different ethnicities could overhaul of the ­definition of a “term birth”, ­providing safer, race-based ­obstetric care.

Results from the study of ­almost 700,000 Victorian births over 11 years, show that mothers born in South Asia (subcontinent), the Middle East, Africa and Europe have a greater stillbirth risk than ­Australian or New Zealand-born women but Southeast Asian-born women have less.

It also showed the risk starts to increase earlier, rising at 37 weeks rather than the recognised standard of 41 weeks, suggesting the placenta “ages” differently for different races.

A South Asian-born woman had 1.5 times the risk of an Australian-born mum, putting her in the same high-risk category as women who smoke, have pre-eclampsia or are obese.

WENDY TUOHY: BEREAVED MUMS WANT PEOPLE TO REMEMBER THEIR LOST CHILDREN

MELBOURNE RESEARCHERS UNCOVERING PLACENTAL STEM CELLS IN AGEING IN BID TO PREVENT STILLBIRTHS

Now researchers from the Hudson Institute of Medical Research and Monash University are looking to uncover why women born in Southeast Asia generally have both a shorter pregnancy and are 40 per cent less likely to have a stillbirth compared to Australian-born mothers.

Lead author, Ritchie Centre research fellow Dr Miranda Davies-Tuck, said previous studies linked stillbirth risk to migration or social disadvantage.

“We’ve found it looks like there might be differences in the gestation length and how the placenta functions, particularly towards the end of pregnancy,” she said.

“Normal clinical guidelines say that, at 41 weeks gestation, all women should be scanned to check their baby and the placenta, and if they’re struggling be offered an induction.

Researchers are working to determine why stillbirth risk differs for maternal ethnicity.

“We know that as the pregnancy progresses the placenta is less able to provide for the baby.

“The risk of stillbirth in Australian-born women at 41 weeks actually commences at 39 weeks for South Asian women. By the time we’re monitoring them at 41 weeks, it might be too late.”

The study is published today in the journal PROS ONE.

Monash Health is trailing new guidelines, funded by Red Nose Day, to test whether more intense monitoring of South Asian-born women in the final weeks of pregnancy could reduce stillbirth.

Co-author Professor Euan Wallace said the team was testing placental tissue to identify biological differences, as well as whether the Southeast Asian diet was protective.

“If we understand what causes the differences ... we could all do the same as what Southeast Asian women are doing or eating, so everyone’s risk comes down,” Prof Wallace said.

Monash Health is trialling new guidelines, funded by Red Nose Day, to test whether more intense monitoring of South Asian-born women in the final weeks of pregnancy can reduce stillbirth.

Co-author Professor Euan Wallace said the team was now testing placental tissue to identify biological differences, as well as investigating whether the South-East Asian diet was protective.

“If we understand what causes the differences, ideally we could all do the same as what South-East Asian women are doing or eating, so everyone’s risk comes down,” Prof Wallace said.

@BrigidOConnell