This study analyses labour market transitions of women in the time around first childbirth. Two employment decisions are considered: exiting the labour force and a reduction in work hours. We assess change in these transitions in the Netherlands between 1970 and 2008. We test whether policy changes, in particular the introduction of unpaid parental leave, have changed the opportunity costs of specific work-family arrangements for women and their partners. We use detailed life-history couple data and estimate multinomial logit models. Our results show that over time, new mothers became less likely to exit the labour market and more likely to reduce their working hours. Eligibility for parental leave and public sector employment reduced the probability of exiting the labour market, but had no effect on reducing working hours. In the 1990s and for those eligible for parental leave, the likelihood that a working hour reduction was associated with a lower job level or an employer change decreased. New mothers with an occupational status at least as high as that of their male partner were less likely to reduce their labour supply. Policy changes did not alter the importance of partners' relative occupational resources.