Abstract Study question What are the experiences of trans and/or non-binary (TNB) parents during the perinatal period (defined here as conception, pregnancy, birth and infant feeding)? Summary answer TNB parents often experience extensive cisgenderist discrimination at a structural level (via inappropriate legislation and bureaucracy) and an interactional level (from other parents/healthcare professionals). What is known already Although TNB people have always parented, it is only recently that their experiences are becoming more socially visible. Some research has explored the pregnancy experiences of trans men, finding that men report feelings of isolation and find it difficult to integrate pregnancy with a male identity. However, little research has explored the perinatal experiences of non-binary parents and TNB non-birth parents. Additionally, preliminary research in the US suggests that TNB parents report negative experiences within fertility clinics, and that some parents deliberately avoid clinics for fear of discrimination, pointing to the importance of studying parents’ experiences in the UK. Study design, size, duration This presentation will focus on interview data collected in a study of UK TNB parents, all of whom had identified as TNB since before having their child. Participants were recruited via social media/snowballing. 13 TNB parents were interviewed in total. This presentation will focus on the experiences of the 10 parents who had become parents via assisted conception at a fertility clinic (n = 5), unassisted conception (n = 4) and known donation (n = 1). Participants/materials, setting, methods Participants had a range of gender identities, including trans women, trans men and non-binary. Six participants had experienced pregnancy. The sample is diverse in terms of SES, family structure, and four parents were experiencing disabilities. Participants took part in a semi-structured interview. The data were analysed using reflexive thematic analysis, and a structural symbolic interactionist framework was employed. Main results and the role of chance Cisnormative understandings of bodies (i.e. men producing sperm and women being pregnant) were found to impact participants in both fertility clinics and pregnancy spaces. Parents with different gender identities (e.g. trans men, non binary people and trans women) had different experiences, pointing to the importance of including all parents under the TNB umbrella within research. In terms of conception, some participants reported avoiding fertility clinics due to fear of discrimination, and one participant described being denied treatment due to their gender identity, disability and being in a multi-parent family. Negative experiences within fertility clinics included clinicians’ lack of knowledge about TNB identities, and more positive experiences were reported when participants conceived outside of a clinical setting. With regards to pregnancy, birth parents reported that pregnancy/birth was assumed to be a female activity, and that services were often exclusively for cis women. Birth parents used the strategy of detachment to navigate pregnancy and infant feeding. The trans women in the study, as non-birth parents, were often assumed to be fathers, and reported feeling excluded in pregnancy spaces. One trans female participant found breastfeeding to be a gender-affirming experience, pointing to the importance of supporting TNB parents to explore all available options. Limitations, reasons for caution The small sample size and qualitative nature of the research limits the generalisability of the findings. Although diverse in other ways, the sample was majority white and more research is needed on the experiences of ethnic minority parents. Wider implications of the findings Findings show the importance of including TNB parents with diverse gender identities within research, and demonstrate the necessity of education about trans-inclusive language and family diversity within fertility clinics and pregnancy spaces. Trial registration number n/a