A study by the Telethon Kids Institute and The University of Western Australia is exploring the reasons why women are delaying pregnancy well into their thirties.
Researcher Jessica Tearne said delayed childbearing is becoming more common in Australia and researchers are trying to find out why.
"There could be many reasons why women are delaying pregnancy such as career, health or relationships," Ms Tearne said.
"We want to know the most common reasons that women are delaying having children until their late thirties or older.
"It's important to know this so we can work out the impacts of delayed pregnancy on mums, kids and families."
The study involves anonymously completing a simple online questionnaire that should take no longer than 30 minutes.
To be eligible to take part, women must be either:
* Currently pregnant, aged 35 or older, and have no other children
* Have given birth for the first time in the past eighteen months, and were 35 or older during the time they were pregnant.
The survey can be completed here.