
We ask why –
so fewer lives are shaped by what if
CanOSS works for a future without preventable pregnancy complications, guided by understanding and driven by action.
It is our duty of care.
Who we are
What is CanOSS?
We are a team of Canadian investigators, spanning diverse disciplines in maternal and postpartum care, crafting a nation-wide survey system to capture pregnancy related morbidity data. Guided by equity and evidence, we collaborate across systems and with communities, listening intently and acting with purpose to prevent complications and ensure no pregnancy is left to chance.


Our process
Topic Selection &
Case Definition
Case
Identification
Local Data Gathering
& Review
Centralized Data Gathering & De-identification
External Confidential Multidisciplinary Review & Feedback to Sites
Consolidating Findings & Recommendations
Knowledge Dissemination & Implementation

Given Canada’s decentralized approach to healthcare delivery and data-sharing, and the diverse healthcare infrastructure between and within provinces and territories, there are several challenges to the development of a standardized survey system. Therefore, CanOSS will first be piloted in Ontario, which holds 38% of Canada’s population. Using feedback from key individuals involved in SMM case review, and informed by the preliminary CanOSS Cycle, existing systems for case review will be optimized and adapted to develop an effective CanOSS-Ontario process. CanOSS-Ontario will be a quality improvement (QI) project, similar to a public health program, that uses a systematic approach to review and evaluate SMM events that occur in Ontario. This system will help to identify opportunities to improve or change practice, and will provide a mechanism to implement such changes. All data entered into the CanOSS-system will be de-identified, and stored at McMaster University.
What we do
Uncovering why, changing how, improving care.
Most research tells us what happened. CanOSS asks why – combining data, clinical expertise, and lived experience to uncover the root causes of severe pregnancy complications. This depth of understanding drives targeted, evidence-based change across healthcare systems, ensuring better care and fewer preventable outcomes.

1

CanOSS National Feasibility Study
Feasibility Study: A Path Toward National Severe Maternal Morbidity (SMM) Surveillance
Our cross-country study confirmed that most Canadian birthing units have SMM review processes and are willing to share anonymized data. These findings support the creation of a Canada-wide obstetric surveillance system to improve maternal health outcomes through evidence-based action.
2

CanOSS Ontario
CanOSS Ontario: A Pilot for Better Maternal Health Surveillance
CanOSS is launching in Ontario to build a province-wide system for reviewing and addressing severe maternal morbidity. Through de-identified data collection, expert collaboration, and equity-informed analysis, CanOSS Ontario will identify opportunities to improve care and reduce preventable harm.
3

CaNCaM-Preg
CaNCaM-Preg: A National Initiative to Improve Cardiovascular Health in Pregnancy
CaNCaM-Preg, one of two initiatives awarded the Research Networks of Excellence in Heart and Brain Healthgrant, has received $5 million in funding to reduce cardiovascular morbidity and mortality in pregnancy. Funded by Heart & Stroke, Brain Canada, and CIHR – Institute of Gender and Health, the initiative uses an interdisciplinary, multi-provincial, and equity-focused approach to address pregnancy-related cardiovascular risk through surveillance, research, and system-level collaboration.
Publications
Core team
Meet our interdisciplinary team working towards the development and establishment of a Canada-wide survey system for pregnancy-related morbidity.
Principal Investigator
Rohan D’Souza
MD PhD FRCOG

Rohan D’Souza is an associate professor in the Departments of Obstetrics & Gynecology and Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario. He has a cross appointment with the Department of Obstetrics & Gynaecology and the Institute of Medical Sciences at the University of Toronto, Ontario. Rohan’s clinical and research interests include reducing severe maternal morbidity, optimizing pregnancy outcomes for individuals with medical disorders, incorporating values and preferences of pregnant individuals into clinical decision making and standardizing outcome reporting in obstetric studies.
Principal Investigator
Isabelle Malhamé
MD MSc FRCPC

Dr. Malhamé is an Assistant Professor and Researcher in the Department of Medicine at the McGill University Health Centre. After residency and sub-specialty training in General Internal Medicine and a Master’s degree in Epidemiology at McGill University, she completed a Fellowship in Obstetric Medicine at the Warren Alpert Medical School of Brown University in Providence, Rhode Island. She provides a specialized clinical service to women with medical disorders before, during, and after pregnancy. Her research program focuses on prediction and prevention of severe maternal morbidity, with a special interest for cardiovascular and thromboembolic complications.
Research Coordinator
Rashid Ahmed
MSc

Rash has a BScH in Ecology from Queen’s University, a MSc in Epidemiology specializing in population and public health and health economics from the Health Research Methodology Program at McMaster University, and a diploma in Applied Community Epidemiology from Community Information and Epidemiological Technologies. He has worked at McMaster since 2001 at the Population Health Research Institute and with the Department of Obstetrics and Gynecology, and is also the Research Manager for the McMaster Midwifery Research Centre. Rash’s interests are in high risk obstetric epidemiology, midwifery research, public health program development, data infrastructures, clinical trials, population health, and health economics.
Research Coordinator
Paige Gehrke
RN, MSc

Paige Gehrke is a research coordinator and registered nurse, with a variety of clinical and research experience. Through her work, Paige endeavors to optimize health system processes to foster safe and positive experiences for clinicians, patients, and families. Paige holds a BScN from Western University, a Critical Care Nursing certificate from Niagara College, and a MSc from McMaster. Paige has collaborated on and led several projects focused on building community hospital research capacity, as well as critical care, moral distress, and qualitative research methods. She has over nine years of clinical experience practicing in a diverse range of settings, mostly situated within intensive care.
Research Coordinator
Angela Wesley
RN., BScN

Angela is a research coordinator and registered nurse with over 24 years of diversified clinical and research experience. She holds a Bachelor of Science in Nursing from the University of Toronto and has dedicated her career to advancing health outcomes through evidence-based practice and compassionate care. Angela’s global health experience includes living and working in Uganda, East Africa, where she served as a regional community health nurse supporting families in underserved communities. She continues to travel to under-resourced areas, contributing to maternal health initiatives that promote safety, education, and equitable access to respectful care. Angela is deeply passional about promoting safe, respectful and inclusive maternal care for all individuals. Through her role with CanOSS, she brings both expertise and advocacy to support improved obstetric outcomes across Canada.