Rebecca Clark can testify to that.

When she went into the maternity ward at Canberra Hospital in early April, the impending major event by caesarean section was overshadowed by extra worry.

"Ten minutes before I went in, we still hadn't been told whether my partner would be allowed in with me," she said. "We need to feel supported during those critical moments but instead I felt stressed from all the uncertainty."

Her pregnancy was during the smoke and bushfires and the birth of Gracie on April 9 was at the height of the lockdown.

She worried about the smoke which smothered Canberra while her baby was in the womb and then feared the virus once Gracie was born.

There was then the additional worry about being locked down and away from all the usual support of family and friends. Nor could she exercise outside, not even pushing the baby in a pram.

"I spent a lot of my pregnancy feeling locked up and stressing over whether the bushfire smoke had had an effect on my baby and because of coronavirus, the stress and uncertainty stayed with me even in those final moments before I had my daughter."

Because of the unprecedented convergence of bad events, a team from the ANU and the Universities of Canberra and Wollongong has come together.

"We need to listen to the experiences of these mothers and look at the challenges they faced during the bushfires and pandemic," Professor Christopher Nolan of the ANU said.

Dr Amita Bansal of the ANU College of Health and Medicine said: "Other bushfire-type studies have indicated that smoke exposure is associated with higher incidence of diabetes and high blood pressure in the mother during pregnancy. Smoke exposure has also been linked with premature birth and reduced birth weight."

But the smoke in the previous studies of American wildfires was from a different source. It was unlike the smoke from burning eucalyptus. One study of smoke and pregnancy was only of coal smoke.

This big study will encompass both Canberra and the south coast of New South Wales.

"I saw many patients who were exposed to significant amounts of bushfire smoke, including pregnant mothers," Surf Beach GP, Dr Michelle Hamrosi, said.

"These patients were also impacted by massive disruption to their normal lives and were filled with anxiety day after day as the fires kept threatening the community. Their physical and mental health suffered."

One mother, Zoey Salucci, was seven months pregnant when the bushfires forced her to evacuate her home in Cobargo with her two-year-old daughter. They sheltered on the beach in Bermagui.

"The smoke was so thick that I couldn't breathe. Being pregnant, your lungs are already squashed and this made it feel so much worse," she said.

"I ended up sitting in a car because I couldn't handle the smoke and I knew I would end up having to run to the beach if the fire got close.

"I was under the most intense and indescribable stress that I have ever experienced. Not knowing how to escape or what the smoke was doing to my baby was the most horrible feeling."

On top of the direct effect of smoke for expectant mothers during the summer, there was then the indirect effect of the lockdown over the spring and winter. Has it affected the mental health of the mothers in their increased isolation?

"There's a lot we don't know about the effect of bushfires and smoke and we want to get some answers," Deborah Davis, professor of midwifery at the University of Canberra, said.

The team wants to hear from women who were pregnant or had a baby no older than three months on February 1, 2020 or became pregnant by April 30, 2020 in Canberra and south-eastern New South Wales.

They promise full confidentially and say the results will help many other mothers in the future.

Click or touch here to contact the researchers for more information or to participate.