This paper examines childbearing among Polish migrant women and their descendants in Sweden. While many studies have focused on immigrants' childbearing in relation to women in the destination country, this study uses a country-of-origin and a country-of-destination approach in order to more thoroughly examine the socialization, selection and adaptation hypotheses. Using a piecewise-exponential model, the transitions to first and second births are analyzed using Swedish register data and the Polish Generations and Gender survey (GGS). The results show that the Polish stayers and the first-generation have relatively similar fertility behavior in the transition to first birth but not in the transition to second birth. However, parts of the similarity in the transition to first birth can be attributed to marital status selection. By examining the 1.5-generation and the second-generation in relation to Swedish natives, it is possible to see fertility convergence across generations, both when it comes to timing and quantum. This study also shows that family migrants have higher risk of having a first child compared to migrants moving for other reasons. However, in the transition to second birth, there is no difference.