This is according to research published online (Wednesday) in Europe's leading reproductive medicine journal
. The study shows that the longer women spent in casual employment, the more likely they were to be childless when they were 35.
The researchers from the University of Adelaide, Australia, found that this association between precarious employment and childlessness at 35 was irrespective of the socioeconomic status of the women.
"Our findings suggest that, regardless of their socioeconomic circumstances, women generally aspire to economic security prior to starting a family. This finding is important because it challenges the pervasive media representations of delayed childbirth as a phenomenon arising from highly educated women choosing to delay motherhood to focus on their careers," write the authors in their paper.
The study was led by Vivienne Moore, Professor in the Discipline of Public Health at the University of Adelaide, and was based on the doctoral study of Emily Steele. The researchers studied data collected from a group of Australian women who took part in the Life Journeys of Young Women Project and who were born between 1973 and 1975 in a large hospital in Adelaide, South Australia. Interviews were conducted with the women in 2007-2009 when they were aged between 32-35 years old to collect information on significant events in their lives such as relationships, childbirth and employment from the age of 15 onwards. If a woman was studying full time, she was considered to be a student and employment during this period was not taken into account.
At the time of the interviews 442 of the 663 women (67%) had given birth to at least one child. At the time of their child's birth or the study's cut-off point, the majority were permanently employed, while 11% were in temporary employment; 225 women (about one-third) had spent no time in temporary employment; one-third had a university qualification and 75% were living with a partner.
The researchers found that the likelihood of childbirth by the age of 35 was reduced for every year spent in temporary employment. One year of causal work was associated with an 8% reduction in the likelihood of a first baby compared to women who had had no temporary jobs; the likelihood of a first baby by around age 35 was reduced by 23% after three years and by 35% after five years of temporary employment.
This effect was seen irrespective of the women's socioeconomic status as indicated by their educational attainment, their partner's education and also their parents' birthplace (as the authors say that migrant families, where one or both parents were born outside Australia, might be more likely to have at least one child at a younger age than other women).
Dr Lynne Giles, co-author and senior lecturer at the university, said: "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.
"Our results also show that having children at an older age and childlessness are not just a matter of individual women's choices. They reflect the broader structural arrangements in society. These over-arching determinants deserve more attention and study so that we can better understand the barriers to family formation."
The authors write in their paper: "Current policy responses generally provide financial and other support to parents after they have children; there remains a need to develop complementary policies to facilitate the ability of couples to commit to family formation." They add: "Since all socioeconomic groups are implicated, we suggest that upstream labour market reforms could be considered in order to remove barriers to child-bearing."
One of the limitations to the study was that the researchers analysed the women's employment history, but not that of their partners. However, they did take the partner's education into account, and they plan to investigate the employment history of both the women and the men in future work.
Although the specific results cannot be extrapolated to other countries, Prof Moore said: "The argument that women's employment conditions have an influence on the timing of family formation would seem to be relevant, especially for Western countries with neoliberal outlook."