The purpose of this project is to examine the effect of parenthood on doctoral students academic socialization and performance. The data consists of doctoral students in medicine, natural science, technology, and the social sciences at a Swedish university. The design is comparative and due to an interest to see how the effect of parenthood varies over scientific disciplines. Parenthood is one of the main explanations of gender differences in performance and career development in academia. A better understanding of how parenthood affects doctoral student outcomes is expected to provide important knowledge of how gender differences arise already during the doctoral education and what we can do to reduce them.