The project is a part of a larger research plan „Divorce and Changes in Reproductive Strategies“. The main purpose of the research is to map changes of social and biological strategies caused by divorce. Within IVRIS will be realized a part dedicated to changes of biological reproductive strategies. The question here is how a divorce affects fertility trajectories for women, as well as men. A combination of quantitative and qualitative methods will be used. In the first case we talk about the secondary analysis of data provided by ČSÚ and data from available surveys. In the other case, we talk about the gathering of biographies and half-standardized interviews.