Every year about half a million women die from complications of pregnancy, parturition and puerperium, most of which are preventable. The purpose of this thesis was to chart the distribution and decline in maternal mortality in Sweden between 1751 and 1980, and furthermore to characterize positive (predisposing) factors and negative (protective) factors of maternal mortality. Maternal mortality declined from 900 to 6.6 per 100,000 live births in these 230 years. Maternal deaths accounted for 10070 of all female deaths in the reproductive ages between 1781 and 1785, but only 0.2.0/0 between 1976 and 1980. However, in the 19th century 40-450/0 of the female deaths in the most active childbearing ages were maternal deaths. The children left motherless had an extremely high mortality. Indirect maternal deaths and puerperal sepsis accounted for the bulk of maternal deaths in the rural areas. Only a minority of maternal deaths occurred in lying-in hospitals. Midwifery services in rural areas and antiseptic techniques were most effective in preventing maternal deaths during the late 19th century. The changing distribution ofage and parity amongst the parturients had a definite impact on the mortality decline, enhanced by time, contributing to 500/0 of the mortality decline over the last 15 years. The expontential decline of cause-specific mortality and case fatality rates during the last 40 years is furthermore explained by the emergence ofmodern medicine - antibiotics, antenatal and obstetric care. The earlier serious problem of illegal abortions was eradicated by legislation and changes in hospital practice. The maternal mortality decline has levelled out during the 1970s, the relative importance of embolism as a cause of death is increasing. Advanced age and intercurrent disease are the most difficult risk factors to overcome. To conclude, this study indicates that the reason why maternal mortality has declined faster than otherhealth indices is that the major part of the maternal deaths can be prevented by medical technology, including family planning, antenatal and obstetric care. This experience should be of interest to developing countries where high rates of maternal mortality prevails.