We analyze individual career transitions of men and women in Germany. Our particular focus is on the association of upward, downward and horizontal job changes with individual fertility. In contrast to most of the literature, we focus on potential rather than realized fertility. Based on mixed multivariate proportional hazard models with competing risks, we find a significant negative relationship between the contemporaneous probability of having a child and horizontal career transitions for women, and a positive significant association of the hazard of parenthood with upward career transitions for men. These effects persist if we apply fixed effects panel data models allowing for correlation of individual parenthood hazards with unobserved individual characteristics. Independent of their sources, our results suggest clear gender differences in the relationship between career patterns and potential fertility.