Previous papers have shown that childrearing has a different impact on a mother's professional career depending on the duration of the maternity leave and on the mother's education level. In this paper, we use a competing risks model to determine which variables may explain the duration of maternity leave, as well as the exit state of the maternity leave. Mothers can decide to go back to the same employer, change employer, change labour supply or drop out of the labour market. Our results show that it is mostly age, wages, tenure, firm size and macroeconomic variables that play a large role in the way young mothers enter the labour market again. We compare our results with those obtained for Germany, and find similar results.