STUDY QUESTION What are the experiences of same-sex mothers following identity-release sperm donation regarding equal treatment in society, parenting stress and disclosure to child? SUMMARY ANSWER Mothers predominantly reported equal treatment in society, low levels of parenting stress and early disclosure of the donor conception to the child, and half of the couples had also informed the child of his/her right to obtain the donors identity. WHAT IS KNOWN ALREADY The number of two-mother families is increasing, and previous studies have reported about challenges related to heteronormativity, discrimination and the status of the non-birth mother. Same-sex mothers have been found to disclose the childs donor conception earlier than different-sex parents, but little is known regarding disclosure of the childs right to obtain identifying information about the donor. STUDY DESIGN, SIZE, DURATION The present study concerns the fourth wave of data collection of a nation-wide longitudinal study. A total of 143 same-sex mothers (73% response rate) following identity-release sperm donation completed individual surveys when their donor-conceived child had reached age 7. These women represent a total of 82 couples who had undergone sperm donation treatment. PARTICIPANTS/MATERIALS, SETTING, METHODS The study is part of the longitudinal Swedish Study on Gamete Donation (SSGD). Couples accepted for gamete donation treatment at seven Swedish University hospitals were recruited between 2005 and 2008 and were requested to complete postal surveys during four waves of data collection. The present study sample includes same-sex mothers who completed a survey when their donor-conceived child had reached 7 years of age. Data were collected with the Swedish Parenting Stress Questionnaire (SPSQ), and study-specific items on experiences of treatment in society and disclosure behavior. Group comparisons (birth mothers vs non-birth mothers) were conducted using Chi(2)-tests, independent t-tests and Mann-Whitney U-tests, and written comments provided for open-response items were analyzed by qualitative content analysis. MAIN RESULTS AND ROLE OF CHANCE The mothers were generally open about the childs donor conception and the large majority (>80%) reported being treated positively and in the same way as other parents. However, satisfaction with treatment in health care settings was significantly lower than that reported in contacts with the childs school and recreational activities (P < 0.001) and open-response comments indicate that this may be related predominantly to heteronormative language and assumptions. Birth mothers and non-birth mothers reported similar treatment in society and similar levels of parenting stress. All but one couple had already talked with their 7-year-old child about his/her conception with donor sperm. Half of the couples had also informed the child about his/her opportunity to obtain identifying information about the donor, and remaining couples planned later disclosure. Childrens reactions were generally described as neutral, positive or characterized by interest and curiosity. LIMITATIONS, REASONS FOR CAUTION The present study was performed within the context of the Swedish legislation on identity-release donation, which limits the generalizability to same-sex couples using anonymous or known sperm donors. Although no evidence of attrition bias was found, it is possible that those couples who initially declined participation in the SSGD (23%) or dropped out at the fourth wave of data collection (27%) differ from the study sample in terms of variables that we were unable to control for. WIDER IMPLICATION OF THE FINDINGS The present finding that most same-sex mothers in a population-based sample experience equal treatment in society is encouraging and validates previous results from predominantly qualitative studies. Nevertheless, the fact that a subgroup experiences discrimination and less favorable treatment indicates that further action is needed, particularly in child health care settings. The present study is the first to report on the timing of parents disclosure of the childs right to identifying donor information and suggests that disclosure during preschool ages is feasible and does not appear to be related to negative consequences. In view of the increased availability and use of identity-release donation, there is a pressing need to investigate parents intentions, behaviors and needs with regard to talking with their child about his/her opportunity to obtain the donors identity. STUDY FUNDING/COMPETING INTEREST(S) Financial support from the Swedish Research Council (2013-2712) and the Swedish Research Council for Health, Working Life and Welfare (2014-00876). There are no conflicts of interest to declare.