Severe Maternal Morbidity Reported in ~3 Percent of Pregnancies
MONDAY, March 16, 2026 (HealthDay News) -- Severe maternal morbidity (SMM) affects almost 3 percent of pregnancies in Ontario between conception and six weeks postpartum, according a study published online March 16 in CMAJ, the journal of the Canadian Medical Association.
Maya Rajasingham, M.P.H., from McMaster University in Hamilton, Ontario, Canada, and colleagues characterized the frequency of SMM from conception to six weeks postpartum in a population-based cohort study of births at 20 or more weeks of gestation using administrative data in Ontario for 2012 to 2021. The frequency of SMM was assessed overall, by period of occurrence, and by SMM type.
The researchers found that the rate of SMM was 27.24 per 1,000 births among 1,095,228 births; 15.63, 55.02, and 29.34 percent of cases occurred antepartum, intrapartum, and postpartum, respectively. Severe hemorrhage overall was the most common SMM type (6.10 per 1,000 births), followed by acute abdomen antepartum (1.94), severe hemorrhage intrapartum (5.28), and sepsis postpartum (4.69). Across periods, there was variation seen in the characteristics associated with SMM; for example, a U-shaped relationship was seen for the frequency of intrapartum and postpartum SMM with maternal age, while antepartum SMM was associated with ages 15 to 19 versus 25 to 34 years (odds ratio, 2.22) but not ages 40 to 49 years.
"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," senior author Giulia Muraca, M.P.H., Ph.D., also from McMaster University, said in a statement. "Improving maternal safety requires a whole-system approach, involving emergency care, primary care, maternity care teams, and postpartum follow-up."
Several authors disclosed ties to the biopharmaceutical industry.