After the birth of a child, women on average work fewer hours and have lower income. But according to economist and PhD candidate Julius Ilciukas, motherhood only partially explains labour market inequality. ‘Often, this inequality already exists before the child is born,’ he says.

Similar groups

To accurately measure the effects of parenthood, Ilciukas analysed data from Dutch couples undergoing fertility treatment. He compared women who successfully became pregnant through this treatment to those who did not, so that the only changing factor was parenthood. ‘Before the treatment, the two groups are very similar,’ says Ilciukas. ‘This allows us to attribute differences after the treatment with reasonable certainty to becoming a parent.’

‘The research findings show that parenthood leads women to work fewer hours, which also reduces their income,’  Ilciukas states in his dissertation. In contrast, men continue to work roughly the same amount after the birth of a child.

Not just the child, also the system

Although motherhood has a clear impact, Ilciukas challenges the idea that children are the sole cause  of inequality. ‘The most important finding of my analysis is that at least half of the gender inequality after parenthood is not caused by children,’ he concludes. In other words: even without children, women would have worse labour market outcomes than men. This means that policy measures focused solely on balancing work and family life, such as free childcare subsidies or parental leave, may not be sufficient to fully close gender gaps in the labour market.

Before parenthood

The results align with earlier research from Sweden and the United Kingdom, which showed that women tend to work significantly less after the birth of their first child,  often until retirement. But Ilciukas’ research shows that this decision is only partly a result of parenthood itself. Other factors also play a role, such as cultural expectations and labour market discrimination.

His research suggests that addressing stereotypical gender roles and improving career opportunities for women before parenthood is just as important as implementing measures after childbirth. ‘We need to look beyond just the desire to have children,’  says Ilciukas.

About the dissertation

Julius Ilciukas obtained his PhD at the UvA on 3 July 2025. His dissertation, titled Fertility and Family, compromises three sub-studies on fertility, parenthood and their effects on labour and family life. The chapter on gender inequality in the labour market is based on data and surveys from Dutch couples who underwent fertility treatment.