Dr Orestis Tsonis (MD, MRCOG, MSc, PhD) is a European Fellow in Reproductive Medicine and a Specialty Doctor in Reproductive Medicine and Assisted Conception at Guy's and St Thomas' NHS Foundation Trust, London, and founder of the TransFertility UK project. He trained in obstetrics and gynaecology in Greece and the UK, holds a PhD in vaginoscopic office hysteroscopy (University of Ioannina) and an MSc in Human Reproduction, and has over ten years' clinical experience, including more than five in assisted conception and fertility preservation.
At Guy's he focuses on urgent oncology and planned fertility-preservation pathways spanning oocyte, embryo and ovarian tissue cryopreservation. He designed and clinically leads the unit's trans-inclusive pathway, now the UK service with the highest number of transgender patients proceeding with fertility preservation before gender-affirming hormone treatment, recognised at the South East London EDI Awards and shortlisted in two categories at the 2025 HSJ Patient Safety Awards.
Elected Junior Deputy of the ESHRE Special Interest Group in Fertility Preservation in 2026, he is faculty on the British Fertility Society's national modules in Fertility Preservation and Creating Modern Families and founded the ACU's 'Education Thursday' multidisciplinary teaching programme. He has published 79 peer-reviewed papers (h-index 17) on fertility preservation, transgender reproductive health, hysteroscopy and chronic endometritis.
Dr Orestis Tsonis (MD, MRCOG, MSc, PhD) is a European Fellow in Reproductive Medicine and a Specialty Doctor in Reproductive Medicine and Assisted Conception at Guy's and St Thomas' NHS Foundation Trust, London, and founder of the TransFertility UK project. He trained in obstetrics and gynaecology in Greece and the UK, holds a PhD in vaginoscopic office hysteroscopy (University of Ioannina) and an MSc in Human Reproduction, and has over ten years' clinical experience, including more than five in assisted conception and fertility preservation.
At Guy's he focuses on urgent oncology and planned fertility-preservation pathways spanning oocyte, embryo and ovarian tissue cryopreservation. He designed and clinically leads the unit's trans-inclusive pathway, now the UK service with the highest number of transgender patients proceeding with fertility preservation before gender-affirming hormone treatment, recognised at the South East London EDI Awards and shortlisted in two categories at the 2025 HSJ Patient Safety Awards.
Elected Junior Deputy of the ESHRE Special Interest Group in Fertility Preservation in 2026, he is faculty on the British Fertility Society's national modules in Fertility Preservation and Creating Modern Families and founded the ACU's 'Education Thursday' multidisciplinary teaching programme. He has published 79 peer-reviewed papers (h-index 17) on fertility preservation, transgender reproductive health, hysteroscopy and chronic endometritis.