Expanding Postpartum Monitoring Could Reveal Missed Cases of Severe Maternal Morbidity
Extending the monitoring period for severe pregnancy complications beyond delivery could significantly improve detection rates, according to new research published in the Canadian Medical Association Journal (CMAJ). The study found that traditional delivery-focused monitoring misses more than 40% of severe maternal morbidity (SMM) cases when surveillance is extended from conception to six weeks postpartum.
What is Severe Maternal Morbidity?
Severe maternal morbidity refers to complications during pregnancy, labor, delivery, or the postpartum period that can result in significant short- or long-term health consequences, including death, extended hospitalization, or lasting disability.
Why Extend the Monitoring Period?
Current practices in Canada primarily focus on monitoring SMM during labor and delivery. Yet, evidence suggests that broadening the surveillance period to encompass conception through six weeks postpartum aligns with guidance from the World Health Organization and could lead to better outcomes. Data from Ontario coroners support this, showing that the majority of maternal deaths occur outside of the labor and delivery window – 47% prenatally and 46% postpartum.
Key Findings of the McMaster University Study
Researchers from McMaster University, Hamilton Health Sciences, and St. Joseph’s Healthcare Hamilton analyzed data from nearly 1.1 million births in Ontario, Canada, between April 1, 2012, and March 31, 2021. The study, utilizing linked administrative and clinical registry data from ICES, revealed a rate of SMM of 27.24 per 1,000 births, translating to approximately 10,000 cases of severe maternal complications annually in Canada.
Common Types of SMM
- Severe hemorrhage
- Severe preeclampsia
- Sepsis
Timing of SMM Events
- 16% of SMM events occurred during the prenatal period.
- 55% occurred during labor and delivery.
- 29% occurred in the six-week postpartum period.
Emergency Department Visits
Nearly 19% of individuals experiencing an SMM event visited an emergency department, particularly during the pre- and postnatal periods, highlighting that severe complications often present outside of traditional obstetric settings.
Risk Factors for SMM
Risk factors for SMM vary depending on the timing of the event.
- Labor and Delivery/Postpartum: Younger and older parents are at higher risk.
- Prenatal: Individuals aged 15-24 years are particularly vulnerable to pregnancy complications.
Common factors associated with SMM across all periods include:
- First pregnancy
- Maternal race
- Pre-existing medical conditions
- Multiple fetus pregnancies
- Immigrant status
- Low income
- Rural/remote residence
- Substance use during pregnancy
- Assault
Type 1 diabetes showed the strongest association with prenatal SMM.
Implications for Maternal Care
“Severe maternal complications aren’t just a delivery room issue – they occur across pregnancy and after birth, and many first appear in emergency departments rather than obstetric units,” says Dr. Giulia Muraca, senior author and perinatal epidemiologist, and an associate professor at McMaster University. “Improving maternal safety requires a whole-system approach, involving emergency care, primary care, maternity care teams, and postpartum follow-up.”
The authors emphasize the need for expanded surveillance to identify and prevent SMM and maternal deaths. They suggest that outpatient surveillance, such as postpartum home monitoring (e.g., heart rate, blood pressure) for individuals at increased risk, is warranted.
The study also highlights the importance of accessible and timely postpartum care, particularly for those at higher risk of SMM, and addresses concerns about decreasing access to ambulatory obstetrical care during the postpartum period in Ontario.
Source: Rajasingham, M., et al. (2026). Severe maternal morbidity from conception to 6 weeks postpartum in Ontario: a population-based, longitudinal cohort study. Canadian Medical Association Journal. DOI: 10.1503/cmaj.251425.