New research published in CMAJ (Canadian Medical Association Journal) indicates that extending the monitoring period for severe pregnancy complications beyond traditional delivery-focused surveillance identifies over 40% more cases. The study extended monitoring from conception to six weeks postpartum, aligning with World Health Organization guidance and data from Ontario coroners showing that most maternal deaths occur outside the labor and delivery window.
Severe maternal morbidity (SMM) encompasses pregnancy complications that can lead to death, extended hospitalization, or long-term disability. Current Canadian practices primarily monitor SMM during labor and delivery, which the study suggests is insufficient.
The research, led by McMaster University, Hamilton Health Sciences, and St. Joseph's Healthcare Hamilton, analyzed almost 1.1 million births in Ontario, Canada, between April 1, 2012, and March 31, 2021. Utilizing linked administrative and clinical registry data from ICES, the study found a significant rate of severe maternal complications.
The study identified an SMM rate of 27.24 per 1000 births, equating to nearly 10,000 individuals experiencing severe maternal complications annually in Canada.
Key Insights from the Ontario Study
The comprehensive analysis revealed several critical findings about the nature and timing of severe maternal morbidity:
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Frequent Complications Identified: Severe hemorrhage, severe preeclampsia, and sepsis were the most frequent types of SMM overall. The research also highlighted specific trends, noting that acute appendicitis was common in the prenatal period, and sepsis frequently occurred in the postpartum period.
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Timing of Severe Events: The study underscored that SMM events are not confined to the delivery room.
Sixteen percent of SMM events occurred prenatally, 55% during labor and delivery, and a substantial 29% in the six-week postpartum period.
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Emergency Department Visits: A significant number of individuals experiencing complications sought urgent care. Nineteen percent of individuals experiencing an SMM event visited an emergency department, primarily during the pre- and postnatal periods, indicating a need for broader care integration.
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Varying Risk Factors by Period: Risk factors for SMM varied depending on when the complication occurred. Complication rates during labor and delivery and postpartum were highest among the youngest and oldest parents, while prenatal complications were particularly common in those aged 15–24 years.
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Common Overarching Factors: Several factors were consistently associated with SMM across all periods. These included first pregnancy, maternal race, pre-existing medical conditions, multiple fetus pregnancies, immigrant status, low income, rural/remote residence, substance use during pregnancy, and assault. Among these, Type 1 diabetes had the strongest association with prenatal SMM.
Redefining Care: A Whole-System Approach
Dr. Giulia Muraca, a senior author and perinatal epidemiologist, emphasized the broader scope of these issues.
"Severe maternal complications occur across pregnancy and after birth, often appearing in emergency departments rather than obstetric units," she stated.
The researchers stressed that focusing solely on the intrapartum period is inadequate for recognizing, preventing, or effectively responding to SMM. They advocate for a whole-system approach involving emergency, primary, and maternity care, as well as robust postpartum follow-up. This includes outpatient surveillance for early identification and prevention of conditions like maternal sepsis. The findings also underscore the critical need for accessible and timely postpartum care, especially for individuals identified as being at higher risk of SMM.