Monitoring Maternal Near Miss/Severe Maternal Morbidity: A Systematic Review

Background: There is international interest in monitoring maternal near miss (MNM)/severe maternal morbidity (SMM). However, there is widespread variability in indicators used to monitor MNM/SMM. Methods: In June 2018, we systematically searched MEDLINE, EMBASE, and CINAHL using terms related to monitoring/surveillance and MNM/SMM. We included papers that used at least three indicators to evaluate MNM/SMM. Using five common indicator sets, we calculated the MNM/SMM rate using hospitalization data obtained from the 2016 US National Inpatient Sample. Findings: Of 18,832 abstracts, 178 papers were included in our review. Overall, 43.3% used the term SMM, 39.9% used MNM, and the remaining 16.9% used a different term. In total, 198 unique indicators were used in studies included in our review; 71.2% (n=141) of indicators were used in 50% of studies included in our review. A single indicator, eclampsia, was assessed in >80% of included studies. The rate of MNM/SMM in American hospitalization data varied depending on the criteria used, with rates ranging from 5.07% (95% CI=5.02, 5.11) with the CDC indicators and 7.85% (95% CI=7.79, 7.91) using the Canadian Perinatal Surveillance system indicators. Interpretation: Our review highlights current inconsistencies in how MNM/SMM is defined and shows there is an urgent need for standardization to promote a concerted global effort in addressing MNM/SMM. Funding: funding was received for this study. Funding Statement: The authors stated: No funding was received for this study. Declaration of Interests: None of the authors had any conflicts of interest to declare. Ethics Approval Statement: As all data used for this study was publicly available, this study was deemed exempt from review by the Conjoint Health Research Ethics Board at the University of Calgary.