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Physician Profiles

Dr. Brenna Ammons

I am a family physician who grew up in the Durham Region. I left Durham for Hamilton to complete my Undergraduate degree in Health Sciences and my Master’s Degree in Research Methodology at McMaster University. My Medical Degree was granted from the University of Toronto. I then returned to Durham to complete my Family Medicine residency via a satellite campus of Queens’ University. Throughout my training I have always been interested in women’s health and obstetrical care.


My passion for obstetrics began at Bowmanville High School during a cooperative education experience delivering babies with local family doctors – and I have been interested in the care of new families ever since.


I am honoured to be part of this great group of Family Physicians. I look forward to providing prenatal, intrapartum, and post-partum care to the families in our community.

Dr. Natasha Aziz

I am thrilled to be a part of Great Expectations Durham. Providing care in pregnancy and for newborns is my favorite part of family medicine.


I grew up in St. John's, Newfoundland and came to Kingston, Ontario to pursue my undergraduate degree at Queen's University. I next completed my medical school at Western in London, Ontario. I came to Durham region to complete my residency training in Family Medicine in the Queen's University program.


During my residency training I was fortunate to meet the group of family doctors who make up GED. I am so grateful to join the team and provide care for pregnancy, delivery and early parenthood.


Outside of work I enjoy hiking, traveling to new places and reading. I also enjoy walking with my partner and our dog. Although my training has taken us to various places, we are now happy to call Durham region home and explore the local trails.


I look forward to meeting you and your growing family.

Dr. Aubrey Kassirer

I am a family physician who likes to think I do pretty much everything in family medicine, except vasectomies. Not that I have anything against vasectomies.

I left Toronto to complete my Bachelor of Science in Biochemistry at McGill University. I then moved to Kingston for medical school at Queen’s University. I completed my Family Medicine Residency at the University of Toronto at Scarborough Hospital. During that time, I spent six months in Orono learning the art of family medicine. I loved the community so much that I set up practice in Orono and then Newcastle.


Since that time, I have maintained my family practice, while continuing to work in the Emergency Department of Lakeridge Health Bowmanville. I also work in urgent care, assist in the operating room, and spend weeks as a hospitalist at Lakeridge.


One of my great medical passions is obstetrics. I spent extra time during my training doing over 300 deliveries. Since then, I have delivered over 500 more babies! I even delivered the last baby born at the Lakeridge Health Bowmanville obstetrics unit (and a few since then in the ER)!

I am married with 4 young boys. Before the birth of our kids, we went travelling and volunteering for four months in Africa, and then for two months to Japan and Thailand. 

Another medical passion of mine is teaching. I have been supervising residents from the University of Toronto’s family medicine residency program since 2002, as a lecturer in that department, but since 2007 I have become more focused on supervising future family physicians from Queen’s University. I am an Associate Professor in the Queen’s Department of Family Medicine.

I am also the Curriculum Lead for the Queen’s Bowmanville Oshawa Lakeridge (QBOL) Family Medicine residency program that started with 8 residents in July of 2012.

Putting together this Family Medicine Obstetrics Group, Great Expectations Durham, has been in the works for many years. I am so excited to have such a great team of family doctors to make this dream come true for all of the women, couples and future babies of Durham!

Dr. Kate Newton

I was born and grew up in the Durham region. I completed by Bachelor of Nursing Sciences at Queen’s University and worked as a nurse for several years in the Emergency room, Intensive care and remote aboriginal communities in Australia. It was during this time that I decided to pursue my dream of becoming a doctor at McMaster Medical School. I always knew I wanted to be a family doctor because of the general knowledge required and the ability to work with people of all ages, and the broad scope of practice including taking care of pregnant women and then their babies. During a medical elective, I met Dr. Kassirer in Newcastle and knew that this was where I wanted to practice! The stars were all aligned as a residency training program opened in Clarington the year I was applying for residency and so I became one of eight residents to train in the area.


I have always been very passionate about athletics and involved in competitive gymnastics, track & field and long distance running. I have completed 8 marathons (in 4 different continents), including the Boston marathon. I continued to run and exercise throughout my pregnancy also.

I am thrilled to be part of Great Expectations! As a new mom, I really understand the benefit of having a family physician follow you throughout pregnancy, then delivery and postpartum period with a focus on the new family unit and all of the adjustments it entails.

Dr. Jaclyn Oldham

I grew up in Whitby, Ontario, and I am so happy to return to Durham to serve the people of this region. Maternity and newborn care has always been a passion of mine, as I have been planning on helping women deliver babies since before high school! I consider it a great honour to care for women during their pregnancy and the birth of their children.


I received a degree in Life Sciences from Queen's University in Kingston, followed by a Doctorate in Medicine from Schulich School of Medicine and Dentistry in London, Ontario. I completed my residency in Family Medicine at Queen's University with rotations in both the Kingston and Oshawa site. I have received additional training in labour support and it is my goal that your delivery will be a positive experience as you meet your new child!


In addition to caring for women during pregnancy and labour, it also brings me great satisfaction to help women meet their breastfeeding goals. I have taken additional courses in breastfeeding through Mohawk College, INFACT Canada, BFI Strategy for Ontario, and Mt. Sinai hospital.


The greatest achievement in my own life has been becoming a mother myself, to a beautiful daughter who has given me unspeakable joy. I am so excited to be able to share in your joy as well as you bring new life into the world! 

Dr. Sarah Ritchie

Like several other members of this group, I grew up in the Durham Region and have been very excited to return to this area to practice Family Medicine and join the Great Expectations Durham group.


I completed my Bachelor of Medical Sciences at Western University, medical school at the University of Ottawa and most recently my residency training at Queen's University. I have always had an interest in Women’s Health, but it was during my residency that I was truly inspired to include Obstetrics as part of my career. I thoroughly enjoy the opportunity to care for women throughout all stages of pregnancy. It is a real privilege to be part of such a joyous milestone in patients’ lives!


My interests outside of medicine include singing, skiing and spending time at my cottage in the Kawarthas.


I look forward to contributing to the growth of happy and healthy families in this community!

Dr. Megan Gao

Dr. Gao has been a locum physician in our group for several years and we are delighted to now have her joining our team as a permanent member. She completed her Family Medicine Residency in 2016 (in the same graduating class as Dr. Aziz!). Her full bio and photo are coming soon.

Dr. Lynn Hiemstra

I am originally from Mississauga, Ontario, and have moved around the province for my training. I did my

undergraduate degree at Western University in London, then medical school at the University of

Toronto, and finally my family medicine program through Queen’s University. I completed my family

medicine training in Durham and had the chance to work with multiple members of the Great

Expectations team. This introduced me to the special role that family doctors can provide from prenatal

care to newborn care.

When I’m not working, I enjoy spending time with my family. I also enjoy cooking, reading, and getting

outside for walks or bike rides.

I am excited to join this group. I look forward to working with you and meeting your family.

Selected Photography by Andrew Stewardson Photography

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