Swedish maternal mortality in the 19th century by different definitions:: previous stillbirths but not multiparity risk factor for maternal death

Background. The high maternal mortality levels in today's developing countries were also found throughout the history of currently affluent countries. The parish information system in Sweden offers unique possibilities for research in historical cohorts. Furthermore, vital events surveillance systems are scarce in today's developing countries. Methods. This cohort study covers 42,387 mothers who gave birth to 150,932 infants during the 19th century in the Skelleftea and Sundsvall areas. Among these women, 1 237 were dead within one year after delivery. The analysis of the cause of these deaths was done according to the various ICD definitions. Parity five and above was defined as grand multiparity. Results. Maternal mortality ratios, deaths per 100,000 live births were as follows: 256.4 (direct obstetric deaths), 320.7 (direct and indirect obstetric deaths), 489.2 (pregnancy-related deaths), 347.8 (late maternal deaths) and 837.0 (maternal deaths and late maternal deaths). In this study, 59% of all maternal deaths occur within the first 42 days of delivery, two thirds of them having direct and indirect obstetric causes. Of the late maternal deaths, the bulk were infectious or other indirect deaths, mirroring more general female mortality and the preexistent endemic situation of tuberculosis and other infectious diseases. The combination of previous stillbirth and infant death represented the highest risk ratios, RR 2.77-3.62, while grand multiparity was not associated with increased risk. Urbanized and industrialized areas tended to have higher maternal mortality. Conclusions. In conclusion, this study shows that the mother's reproductive history was the most important risk factor measured for all definitions of maternal death. Grand multiparity did not increase the risk of maternal death. Maternal mortality ratio varied threefold in the study population, depending on the definition used. The high mortality ratios found in this study, only declining by the end of the century, should be interpreted as a general condition of the society since no significant differences could be perceived regarding social class, while unmarried women were more at risk.