Why women in some countries are more likely than others to postpone childbirth when facing employment instability? This study uses 2010–2019 EU-SILC panel data to explore whether the impacts of women’s employment instability, including being unemployed or temporarily employed by fixed-term contracts, on the first- and second-birth transitions differ across 27 European countries and how governments’ provisions of different family policies moderate such relationships. Results showed that while unemployment and temporary employment could generally delay women’s first- and second-birth transition, such effects varied across European countries and depended on the levels of family policy provisions. Countries with more generous family cash benefits were associated with less negative and even positive effects of women’s employment instability on birth transitions. On the other hand, the birth effects of women’s employment instability did not vary significantly across countries according to the length of paid maternity/parental leaves. Most strikingly, countries with higher childcare coverage rates were associated with more negative effects of women’s employment instability on birth transitions. These findings highlight the importance of family policy contexts in shaping women’s childbirth responses to unstable employment circumstances.