Co-founder and Medical Director of Twig Fertility, Dr. Rhonda Zwingerman is a physician and reproductive endocrinology and infertility (REI) specialist.
She completed medical school at Queen’s University, OBGYN residency at the University of Alberta, and her Masters and REI fellowship at the University of Toronto. She sits on the REI and Genetics Committees of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and is the co-author of the Canadian guideline on preimplantation genetic testing. Her clinical and research interests include pregnancy outcomes after IVF, early pregnancy care of fertility patients, and reproductive genetics.
Having gone through IVF herself, she understands first-hand how difficult it is to need the help of a fertility clinic and to undergo treatment. She is committed to modernizing fertility care through the use of best-in-class technologies and to building a clinic that provides people with comprehensive and compassionate fertility care.
An avid musical theatre buff, Dr. Zwingerman sits on the board of the Musical Stage Company, Canada’s leading and largest non-profit dedicated to musical theatre. When not working, spending time with her family or at the theatre, she’s planning her next theatre-related trip to NYC.
Dr. Rhonda Zwingerman (she/her)
Medical Director & Co-Founder
Dr. Ruth Ronn is deputy medical director at Twig and brings a wealth of experience from her work on the frontlines of fertility – both in Canada and abroad. A Royal College certified Obstetrician Gynaecologist and Reproductive Endocrinology & Infertility (REI) specialist, she is a graduate of McGill Medical School and trained in Obstetrics and Gynaecology at Queen’s University.
Dr. Ronn completed her Reproductive Endocrinology & Infertility (REI) Fellowship at Mount Sinai Hospital, University of Toronto, and received her Masters in Public Health at Johns Hopkins University. She has trained with world leaders in infertility both in Israel and in Canada and is the recipient of numerous scholarships, awards, and research grants.
Dr. Ronn has pursued a variety of research initiatives and continues to carefully follow challenges in fertility preservation and disparities in fertility care. She has published in peer reviewed medical journals, presented at national and international conferences, and has helped author the Canadian Guidelines on Fertility Preservation.
She is currently working on national guidelines towards inclusive fertility care for sexual and gender minorities.
In addition to her daily practice as an infertility specialist, she is passionate about yoga, outdoor activities, and travel.
Dr. Ruth Ronn (she/her)
Deputy Medical Director
As the Lab Director at Twig Fertility, Christine brings to the team a diverse and multi-faceted background in fertility and reproductive biology. It is through her passion for evidence-based research and overall exposure to multiple parts of the patient journey, that Christine has meticulously designed our laboratory – incorporating best practices from leading clinics across North America, and intertwining them into workflows that take a holistic view of the entire patient experience.
Her reproductive journey started with a Master’s degree from McGill University where she studied the key factors of embryo implantation. Following her thesis work, Christine entered into the world of fertility as a clinical embryologist and over the course of her career has been part of the teams in three leading fertility clinics in Canada.
Building upon her experiences in embryology, Christine then joined Igenomix, a leading genetic testing service provider specialized in fertility and reproductive health. At Igenomix, Christine set up two laboratory sites and was responsible for overseeing Canadian operations, as well as advising physicians across the US and Canada on genetic services, including endometrial receptivity and microbiome testing.
Christine is a member of the Canadian Fertility and Andrology Society (CFAS), the European Society of Human Reproduction and Embryology (ESHRE) and the Society of Obstetricians and Gynaecologists of Canada (SOGC).
A mother to two young kids and a dog, Zoe, Christine is also a certified yoga instructor and an avid backpacking camper. She is also a PADI certified SCUBA diver and has spent time diving and studying blacktip and ragged tooth sharks, supporting research in Aliwal Shoal, South Africa.
Christine Sykas Yeh (she/her)
Michelle is a registered nurse with over 12 years experience in obstetrics, gynaecology and fertility, focused on providing the highest level of care and compassion to all patients and their families.
She completed a Bachelor of Science in Nursing at Seneca College/York University Collaborative Program, as well as a certificate in Reproductive Endocrinology and Infertility from the American Society of Reproductive Medicine and is currently earning her Masters of Nursing degree at Athabasca University. Michelle is also a member of the Canadian Fertility and Andrology Society (CFAS).
A mother of twins, Michelle also enjoys hiking, cycling, spending time outdoors, studying and playing with her kids.
Michelle Moniz (she/her)
Clinic & Nurse Manager
Erin brings to Twig over ten years of experience, seven as a primary care Nurse Practitioner. She completed a Bachelor of Arts in Psychology and Women’s Studies and a Bachelor of Science in Nursing at Trent University, and a Master of Nursing at Athabasca University. Erin brings with her a deep expertise in inclusive reproductive and sexual health care serving people of all genders and sexualities.
Erin Barnes (she/her)
Prior to joining Twig Fertility, Daria had worked for twelve years in the areas of labour and delivery, and high risk obstetrics. After pursuing her Nurse Practitioner, she held a variety of roles, including taking care of women in the prenatal and postpartum periods.
Daria Gefrerer (she/her)
Dr. Ryan Fitzpatrick is a Urologist with subspecialty fellowship training in Male Infertility and Andrology.
He completed medical school at Queen’s University, Urology residency at the University of Ottawa and Infertility Fellowship Training at the University of Toronto. He currently also works as a Urologist at Mackenzie Health. His clinical interests surround optimizing male fertility and helping maximize patients success going into any assisted reproduction treatments. He is committed to improving the societal barriers around requiring fertility care and providing complete and compassionate fertility care to all of his patients. When not in the clinic, Dr. Fitzpatrick is an avid traveler and a big Raptors fan.
Dr. Ryan Fitzpatrick (he/him)
Dr. Hossain is a fifth-year resident physician with the Department of Psychiatry at the University of Toronto. He has a career interest in the field of obsessive-compulsive and related disorders and has prior experience conducting research on issues of homelessness and access to health care.
Given his lifelong diversity of interests (his undergraduate degree was in theatre), Dr. Hossain comes to Twig with his trademark curiousity to learn, help, and grow alongside patients and their families.
Dr. Rahat Hossain (he/him)
Heather earned her Master’s of Science in Genetic Counselling from the University of Toronto and is certified by both the Canadian and American Boards of Genetic Counselling. She began her career at the world’s first psychiatric genetic counselling clinic in Vancouver BC, where her research work focused on perinatal and postpartum mental health. Heather’s clinical experience has made her passionate about removing barriers for fertility patients to access comprehensive preconception and prenatal genetic services in the context of an integrated and supportive care team, and she is excited to have the opportunity to put this into action at Twig.
Outside of the clinic, you can find Heather spending quality time with family and friends, staying active with hiking and rock climbing, and volunteering with Shelter Movers to help survivors of abuse transition to safer lives.
Heather Andrighetti (she/her)
As the Reproductive Counsellor at Twig, Elisa will support and empower patients during their fertility journeys through individual, relationship, and group checkin-ins and counselling. She fosters an anti-oppressive and trauma-informed practice founded on non-judgement, creativity, and kindness. She is experienced working with members of the LGBT2SQ+ community, with non-traditional families, and has training in group work, narrative therapy, emotionally-focused therapy (EFT), and cognitive-behavioral therapy (CBT). When not at Twig, Elisa works as a relationship and sex therapist in private practice.
Elisa is a Registered Social Worker with the Ontario College of Social Workers and Social Service Workers (OCSWSSW). She earned her Master’s in Social Work from Loyola University Chicago and is a trained advocate for survivors of sexual assault and gender-based violence. She is a member of the Ontario Association of Social Workers (OASW), Canadian Fertility and Andrology Society (CFAS), the International Association of Social Work with Groups (IASWG), and volunteers at Stella’s Place, a mental health centre for young adults in Toronto.
In her free time, Elisa is a musician who learns and performs traditional world harmony singing, old-time music, and Appalachian clogging. She is a quilter, a birder, a vacuumer of dog hair, and is working on planting a pollinator-friendly garden in her yard.
Elisa Gores (she/her)