‘40 weeks’: New research is changing clinical practice to prevent stillbirth

Stillbirth is one of the most devastating outcomes to a pregnancy that a parent could imagine. Yet, in Australia, it remains common – one in 135 births will result in a stillbirth and this figure has not improved in two decades, but there is hope on the horizon.

New research by Dr Miranda Davies-Tuck is changing the way women are cared for in the final weeks of their pregnancy to better ensure the good health of their baby and reduce the rates of stillbirth.

Dr Davies-Tuck’s research redefines a ‘term’ birth by showing the average length of a pregnancy is not always the universal 40 weeks that has been widely applied. Her findings show pregnancy length may differ, based on a mother’s ethnic background or country of origin.

“These findings could completely change how we define what a ‘term’ and ‘post-term’ birth is in clinical care,” says Dr Davies-Tuck, a research fellow in The Ritchie Centre.

Ethnicity ‘an independent risk factor for stillbirth’

The study of almost 700,000 births and stillbirths in Victoria between 2000 and 2011 found that pregnant women born in South Asian countries, such as India, Sri Lanka or Afghanistan, were at an increased risk of having a stillbirth in late-term pregnancy.

The average natural onset of labour occurred earlier in women born in South Asia, at 39 weeks, compared to 40 weeks for women born in Australia or New Zealand, suggesting the time at which a placenta can no longer sustain a fetus may differ across ethnic groups.

“Currently, a mother’s country of birth is considered a risk factor for stillbirth, but only in the context of migration and socioeconomic factors. This study confirms a mother’s country of origin or ethnicity is an independent risk factor for stillbirth,” Dr Davies-Tuck says.

Setting the ‘placental alarm clock’ earlier

Current clinical guidelines advise that pregnant women undergo fetal surveillance or have the option of having their labours induced at 41 weeks of gestation to best prevent stillbirth.

“For women born in South Asia and Africa, 41 weeks may be too late, and we may need to set the placental ‘alarm clock’ earlier, for example at 39 weeks of gestation, to help prevent stillbirth in these women,” Dr Davies-Tuck says.

Based on the findings, Monash Women’s has started a trial of ethnic-specific guidelines to better monitor women during pregnancy and reduce the rates of stillbirth.

“It is vital that we identify which mothers are most at risk of stillbirth, and exactly when that is. Our study is leading to changes in clinical practice that may reduce the rates of late-term stillbirth,” Dr Davies-Tuck said.

The research, co-authored by Professor Euan Wallace of Monash Women’s, and Monash University Research Fellow, Dr Mary-Ann Davey, was published in the journal PLOS One.

Stillbirth facts

Findings from the study of births and stillbirths in Victorian hospitals between 2000-2011.

  • The overall stillbirth rate for South Asian born mothers was 5.1 per 1000 births, compared to 3.3 stillbirths for Australian and New Zealand born mothers.
  • The stillbirth rate was also higher in African and Middle Eastern born mothers (4.4 per 1000 births) and lower in South East Asian mothers (2.4 in 1000 births).
  • South Asian born mothers were 27 per cent more likely to experience stillbirth than Australian born mothers.
  • Women born in South Asia, the Middle East and Africa were more likely to have a late-term stillbirth (after 37 weeks’ gestation) than women born in Australia, New Zealand, Europe or South East Asia.


Dr Miranda Davies-Tuck, Professor Euan Wallace, Dr Mary-Ann Davey.