More babies born underweight and pre-term after floods: study

Babies born early and at a lower weight followed catastrophic Australian floods, a new study has found, as doctors raise concerns about the impact of climate change on pregnant women.

The researchers found mothers who likely experienced a flood incident in the six months leading up to their pregnancy had higher rates of low birth weight for babies born full-term, and babies being small for their gestational age.

Heavy flooding at Windsor, in north-west Sydney, in July 2022.Credit: Brook Mitchell

Mothers estimated as having experienced a flood during the first trimester of their pregnancy were more likely to have a pre-term or still birth.

In contrast, flood exposures during the second and third trimesters were associated with reduced risks.

It is the first Australian study, published in The Lancet Planetary, to attempt to assess how living through major flood and storm event impacts a mother’s birth outcomes, covering 1.3 million babies born between 2001 and 2020 in Sydney and 1995 to 2014 in Brisbane.

This time period included major storm events in Sydney during the summers of 2019 and 2020, where flooding destroyed homes on the city’s semi-rural fringe, blocked roads and left tens of thousands of people without power, as well as Brisbane’s historic 2011 flood.

Study co-author Professor Yuming Guo said risks of adverse birth outcomes could be increased by maternal exposure to non-optimal or hazardous environments, the mother’s immune system and health status being compromised, maternal stress, and insufficient midwifery care during and after flooding events.

“It is important to understand the associations between floods and adverse birth outcomes to be able to plan for both pre-pregnancy and perinatal risk assessments and managements, if climate change is likely to increase the risk of flooding event,” he said.

In its submission to federal senator David Pocock’s climate change “duty of care” bill, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists said a growing body of evidence was linking an increased risk of adverse birth outcomes to exposure to environmental disasters, toxic pollution, heat, poor nutrition and stress.

“Although there are many underlying causes for miscarriage and stillbirth, some unpreventable, the excess risk seen in association with certain environmental exposures can be seen as representing a denial of life to otherwise healthy children,” it wrote.

‘Trying to prevent health harm is our number one priority, and climate change is the greatest threat to human health of the 21st century,’

Dr Michael Williams, from Doctors for the Environment

Dr Kristine Barnden, chair of the college’s Environmental Sustainability Working Group, said the Monash study fit with what was already known about the impact of any major stressor, whether it be environmental or social, on pregnancy.

“Most of the attention has been on the impact of heat and air pollution, so this is a somewhat novel study,” she said.

However, she queried whether it was fair to say the results found by the researchers reflected poor maternal care, even if that may be a problem facing pregnant women impacted by a natural disaster, such as a bushfire or flood.

Dr Michael Williams, a Queensland paediatrician and spokesperson for Doctors for the Environment Australia, said the study fit into the picture of severe harm fossil fuels were causing through driving climate change.

Adam and Naomi McGowen with their son Austin, in February last year. Credit: Brook Mitchell

“As health professionals, trying to prevent health harm is our number one priority, and climate change, driven by fossil fuels, is the greatest threat to human health of the 21st century,” he said.

Naomi McGowen was six weeks pregnant when floodwaters destroyed her home in Lismore, in northern NSW, in 2022. She and her husband, Adam, climbed onto their roof to survive.

While she says she was lucky that the two hospitals in the town were outside the flood zone, Naomi’s doctor’s office was shut down and her care ended up costing more than it would have otherwise.

“There were bulk billing places before the flood, but they got wiped out, so I had to pay for all the scans,” she said.

The McGowens’ son, Austin, will turn two in November. The stress of the flood continued throughout her pregnancy and beyond, Naomi said.

“It’s something that will always flicker back. You go back to where we were living and remember how it was,” she said.

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