BACKGROUND : The Mother-Generated Index (MGI) assesses postnatal quality of life (QoL) without providing a predefined checklist, thus offering mothers the opportunity to identify areas of life affected by having a baby. OBJECTIVE : To identify: (a) details and particularities of areas of life affected after childbirth and thus specific domains defining postnatal quality of life; (b) changes in the importance of domains specifying QoL within the first weeks postpartum; and (c) the potential role of cultural differences with regard to the nature of QoL definitions. METHODS : Prospective, cross-cultural, longitudinal survey. We applied a qualitative content analysis to Mother-Generated Index data collected in Switzerland and Germany using combined deductively and inductively category building. RESULTS : Women participated at three days (n=124) and six and a half weeks (n=82) postpartum. Eleven domains were identified, each with several subdomains: 'physical well-being' (e.g. fatigue), 'psychological well-being' (e.g. happiness, emotional confusion), 'general well-being', 'motherhood' (e.g. bonding with the baby), 'family and partnership' (e.g. time for partner and children), 'social life' (e.g. friends, being isolated), 'everyday life' (e.g. organisation daily routine), 'leisure' (e.g. less time), 'work life' (e.g. worries about job), 'financial issues' (e.g. less money), and further aspects. The most frequently indicated domains were 'motherhood' and 'family and partnership'. Differences between the stages of assessment and countries were identified. CONCLUSIONS : Mothers faced challenges in defining their new role but welcomed the slowdown in the rhythm of life and experienced overwhelming maternal feelings. CONCLUSIONS : Our findings suggest that postnatal quality of life is a concept that changes over time and differs between countries.