Validity of a minimally invasive autopsy for cause of death determination in maternal deaths in Mozambique: An observational study

Background Despite global health efforts to reduce maternal mortality, rates continue to be unacceptably high in large parts of the world. Feasible, acceptable, and accurate postmortem sampling methods could provide the necessary evidence to improve the understanding of the real causes of maternal mortality, guiding the design of interventions to reduce this burden. Methods and findings The validity of a minimally invasive autopsy (MIA) method in determining the cause of death was assessed in an observational study in 57 maternal deaths by comparing the results of the MIA with those of the gold standard (complete diagnostic autopsy [CDA], which includes any available clinical information). Concordance between the MIA and the gold standard diagnostic categories was assessed by the kappa statistic, and the sensitivity, specificity, positive and negative predictive values and their 95% confidence intervals (95% CI) to identify the categories of diagnoses were estimated. The main limitation of the study is that both the MIA and the CDA include some degree of subjective interpretation in the attribution of cause of death. A cause of death was identified in the CDA in 98% (56/57) of cases, with indirect obstetric conditions accounting for 32 (56%) deaths and direct obstetric complications for 24 (42%) deaths. Nonobstetric infectious diseases (22/32, 69%) and obstetric hemorrhage (13/24, 54%) were the most common causes of death among indirect and direct obstetric conditions, respectively. Thirty-six (63%) women were HIV positive, and HIV-related conditions accounted for 16 (28%) of all deaths. Cerebral malaria caused 4 (7%) deaths. The MIA identified a cause of death in 86% of women. The overall concordance of the MIA with the CDA was moderate (kappa = 0.48, 95% CI: 0.31–0.66). Both methods agreed in 68% of the diagnostic categories and the agreement was higher for indirect (91%) than for direct obstetric causes (38%). All HIV infections and cerebral malaria cases were identified in the MIA. The main limitation of the technique is its relatively low performance for identifying obstetric causes of death in the absence of clinical information. Conclusions The MIA procedure could be a valuable tool to determine the causes of maternal death, especially for indirect obstetric conditions, most of which are infectious diseases. The information provided by the MIA could help to prioritize interventions to reduce maternal mortality and to monitor progress towards achieving global health targets.
In an observational study, Clara Menéndez and colleagues assess the concordance of minimally invasive autopsy with complete diagnostic autopsy in cases of maternal death.
Author summary Why was this study done? Since 1990, the maternal mortality ratio (MMR) has dropped by 43%, but despite this progress, hundreds of women still die every day in large parts of the world due to pregnancy or childbirth complications. A reliable knowledge of the causes of maternal death is a necessary condition to reduce this burden through adequate health planning. Current methods, such as verbal autopsies or the review of clinical data, have shown a high degree of misclassification in this specific group of deaths. We aimed to validate a minimally invasive autopsy (MIA) approach as a possible complement to verbal autopsies by comparing its performance against the complete diagnostic autopsy, the gold standard for cause of death investigation. What did the researchers do and find? We performed paired MIA and CDA in 57 maternal deaths that occurred at the Maputo Central Hospital, Mozambique, and assessed the concordance between both methods. Indirect obstetric diseases caused 56% of all deaths and direct obstetric complications accounted for 42% of deaths. Infectious diseases and obstetric hemorrhage were the most common causes of death among indirect and direct obstetric conditions, respectively. The overall concordance of the MIA with the CDA was moderate and both methods agreed in 68% of the diagnostic categories. The etiological microorganisms in infectious diseases causes of death were identified in 67% of the MIAs. What do these findings mean? The MIA procedure could be a valuable tool to determine the causes of maternal death, especially in indirect obstetric conditions, most of which are infectious diseases. This information may be helpful for decision-making on health planning and prioritization of interventions to reduce maternal mortality and for monitoring progress towards achieving global health targets.