Melbourne university students' biological clocks are ticking faster than they realise, new research reveals.

Only 45 per cent of women and 38 per cent of men the 1215 University of Melbourne students surveyed knew female fertility declined between age 35-39, the paper published in Human Fertility reveals.

Fewer than one-in-five participants also identified male fertility declining between 45 to 49 years.

Yet, having children was equally important to both men and women with many expecting to achieve other life goals before becoming parents.

"University students overwhelmingly want to be parents one day. However, most also have unrealistic expectations of what they want to achieve before having children, whether that be in their career or financially," Victorian Assisted Reproductive Treatment Authority's (VARTA) Eugenie Prior said.

"We need to educate young people about the limits of fertility and support them to become parents at a point that is ideal biologically, while balanced against the life goals they want to achieve."

Dr Prior, who is the lead author, surveyed students in an online anonymous questionnaire in March about their intentions, expectations for parenthood and fertility knowledge.

The report also revealed, of those who did want children, three-quarters wanted two or more.

Being in a stable relationship, sharing responsibility with their partner and feeling sufficiently mature were rated as the most important conditions prior to having children, the report published in July finds.

Yet women were more likely than men to put importance on completing their studies, advancing in their profession, having work that could be combined with parenthood and access to child care.

Co-author Raelia Lew, who is a reproductive endocrinologist and fertility specialist at the Royal Women's Hospital in Melbourne, said there was "a big social disconnect between young people's views and goals, and biological reality".

The study recommends the government adopt policies to make flexible working hours for people with young children mandatory and increase support for access to high-quality and affordable child care.

"Such policies might reduce the conflicts young people might face between family formation and other life goals and give both men and women confidence to start their families at a younger age," the paper reads.

VARTA and Family Planning Victoria have made a fertility and assisted reproductive treatment teaching tool for schools to raise awareness about factors which may impact fertility.