Dr Orestis Tsonis

Dr Orestis Tsonis, MD, MRCOG, MSc, PhD, EFRM

Specialist in Reproductive Medicine, Fertility Preservation and Gynaecological Surgery

Dr Orestis Tsonis is a London-based specialist in reproductive medicine and gynaecology at Guy’s and St Thomas’ NHS Foundation Trust, combining advanced clinical expertise with an extensive academic and research background.

With a particular focus on assisted reproduction, reproductive surgery and fertility preservation, Dr Tsonis has developed expertise in the investigation and management of infertility, assisted conception, reproductive endocrinology and complex reproductive healthcare.

He holds the prestigious European Fellowship in Reproductive Medicine (EFRM), awarded through the European Society of Human Reproduction and Embryology (ESHRE), alongside a PhD, an MSc and Membership of the Royal College of Obstetricians and Gynaecologists (MRCOG).

A particular area of distinction is his work in fertility preservation. At Guy’s and St Thomas’, Dr Tsonis plays a leading clinical role in delivering specialist fertility preservation care for patients facing cancer treatment, individuals with complex medical conditions and transgender and gender-diverse people seeking to preserve their reproductive options.

His clinical approach brings together advanced reproductive medicine, evidence-based counselling and individualised fertility preservation strategies, including oocyte, embryo and sperm cryopreservation.

Alongside assisted conception, his clinical interests encompass minimally invasive gynaecological surgery, hysteroscopy, endometriosis, fibroids and fertility-related gynaecological conditions, reflecting his commitment to integrating medical and surgical approaches to reproductive healthcare.

Beyond clinical practice, Dr Tsonis is an active researcher, published academic and contributor to international reproductive medicine. His research spans oncofertility, reproductive outcomes, fertility preservation, reproductive autonomy and inclusive reproductive healthcare. He has contributed to peer-reviewed scientific publications and presented his work at international scientific meetings.

He also serves as Junior Deputy of the ESHRE Special Interest Group in Fertility Preservation, contributing to international professional collaboration and the advancement of fertility preservation practice.

Dr Tsonis believes that exceptional reproductive healthcare requires more than technical expertise. His approach combines scientific rigour, clinical precision, clear communication and respect for each patient’s individual circumstances, values and reproductive ambitions.

His professional philosophy is straightforward: patients deserve reproductive care informed by the best available science, delivered with expertise, honesty and genuine respect for their autonomy.