Today’s women are having their first child later in life. According to the CDC, women in the US bear their first child at an average age of 25.6. But a new study suggests a woman’s employment status may influence the age of first childbirth, with prolonged temporary employment causing a woman to be childless up to the age of 35.

Researchers from the University of Adelaide in Australia say their findings show that women generally aspire to economic security before starting a family, which challenges the general belief that women choose to have a child later in life to focus on their careers.

Dr. Lynne Giles, of the University of Adelaide and co-author of the study, explained the reasons behind conducting this study to Medical News Today:

“Casual employment has become increasingly prevalent in many Western societies, and we hypothesized that it might be an important precursor to women having children at older ages.”

To reach their findings, published in the journal Human Reproduction, the investigators used data from 663 Australian women involved in the Life Journeys of Young Women Project. All women were born between 1973 and 1975 in Adelaide.

Between 2007 and 2009, when the women were aged between 32 and 35, they were interviewed and provided information regarding certain events in their lives. This included information on relationships, childbirth and employment from the age of 15.

The researchers note that if a woman was studying full-time, she was classed as a student and employment during this period was not taken into consideration.

It was found that at the time of the interviews, 442 (67%) women had given birth to at least one child.

Looking at employment data either at the time of their child’s birth or at the cut-off point of the study, it was found the majority of women were permanently employed, while 11% were in temporary employment.

Around one-third of the women had not spent any time in temporary employment, one-third had a university qualification and 75% were living with a partner.

When looking at patterns of employment and age of first childbirth, the researchers found that the longer women spent in temporary employment, the less likely they were to have their first child by the age of 35.

In detail, 1 year of temporary employment was linked to an 8% reduction in the likelihood of a first child by age 35, compared with women who had spent no time in casual work. After 3 years in temporary work, the likelihood was reduced by 23%, and after 5 years, this reduced further to 35%.

This link was still apparent after taking into consideration the women’s socioeconomic status, their partner’s education and their parent’s birthplace, the researchers note.

Explaining the findings further, Dr. Giles says:

“Our results showed that 61% of women who had received a university education had at least one casual job after achieving their first qualification, and 30% of these jobs were managerial or professional. This highlights the fact that temporary employment is no longer the sole domain of low-skilled, poorly paid people.”

She told Medical News Today:

The results were not surprising to us, but the findings do challenge some common representations of delayed childbirth as a phenomenon arising from highly educated women choosing to delay motherhood to focus on their careers.”

The researchers point out that current policies generally provide financial support to parents after they have had children, but they note that there need to be policies in place in order to “facilitate the ability of couples to commit to family formation.”

The investigators say that a limitation in their study was the fact that they only analyzed women’s employment history and not that of their partners. But they note that future research will take both factors into account.

“We are looking to deepen our understanding of the barriers to family formation that arise through societal structures. We are planning some research that examines the dual roles of women’s and partner’s employment histories in family formation and its timing,” Dr. Giles added.

Medical News Today recently reported on a study revealing that multiple births cost disproportionately more than single births.