Mark Peter Leondires MD

Dr. Mark P. Leondires is the Founder, Medical Director, and Partner in reproductive endocrinology at Illume Fertility and Gay Parents To Be. He is board-certified in both Obstetrics and Gynecology and Reproductive Endocrinology and Infertility.

He has served as a member of RESOLVE's Physician Council and as Chair of ASRM's LGBTQ Special Interest Group. Dr. Leondires has been selected as a Castle Connolly "Top Doctor" in CT & NY for many consecutive years.

For Dr. Leondires, medicine offers an opportunity to solve problems; each fertility patient presents a unique puzzle. This, combined with a wide range of interests and life events, is how Dr. Leondires came into reproductive endocrinology and infertility and started his own fertility practice.

After his undergraduate years, Dr. Leondires went to Harvard University to study angiogenesis, the development of new blood vessel formation. This appealed to his desire to study complex science, and he continued as an EMT to work as an EMT. The latter met his needs to combine science and working with people. Eventually, he went to medical school at the University of Vermont in Burlington, VT, where he was able to combine his interests in science, helping people, and, of course, fixing things.

Dr. Leondires completed his residency in Obstetrics and Gynecology at Maine Medical Center in Portland, Maine, which was followed by a fellowship in Reproductive Endocrinology and Infertility at the National Institutes of Health in Bethesda, Maryland.

As a resident, Dr. Leondires experienced a range of specialties. Initially, he was most interested in the pediatrics rotation, but in the last week, he worked with a reproductive endocrinologist and infertility specialist. To his surprise, this spoke to him and pointed him on his path to becoming a fertility specialist.

After medical school, Dr. Leondires served as the Director of Assisted Reproductive Technologies at the Combined Federal Program for Reproductive Endocrinology. While under his direction, the ART Program was one of the most successful in the Washington DC area and in the top tenth percentile nationally. During this time he was an Assistant Professor at the Uniformed Services University of Health Sciences and clinical faculty for the Combined Fellowship in Reproductive Endocrinology.

Another puzzle Dr. Leondires has worked diligently to solve is family building for the LGBTQ+ community. When he became a parent with his partner, he recognized the limited options available to the LGBTQ+ community, which led him to create and launch Gay Parents To Be, an educational resource supporting LGBTQ+ couples and individuals on their own family-building journeys.

While his academic and professional career has led Dr. Leondires to spend his time in labs, hospitals, and medical offices, he has not abandoned his love for biology and the outdoors. Dr. Leondires spends much of his time at the beach, teaching his two young boys about the marine life of the Long Island Sound. He loves being outdoors hiking, biking and skiing. Dr. Leondires is a dedicated father to his two sons and his husband, whom he married in 2009.