The Causes and Determinants of Maternal Mortality
Three conditions - puerperal sepsis, toxemia, and hemorrhage - caused the majority of maternal deaths throughout the developed world from the mid-nineteenth century until the mid-1930s, and the proportion of total deaths contributed by each was remarkably constant in different countries during this period.
Puerperal sepsis usually accounted for about 40 percent of deaths. At first, the term puerperal sepsis was synonymous with puerperal fever (“childbed fever”), an infection that appeared after delivery. Later, it included septic abortion as well, but in most countries the two were not distinguished until the late 1920s, when deaths from septic abortion were increasing, although to a widely different extent in different countries. By the early 1930s, the death rate from septic abortion had reached a high level in the United States. In New Zealand, deaths from septic abortion actually exceeded those from full-term sepsis. The contribution of septic abortion to mater-
nal mortality in different countries is an extremely complex subject. But it is likely that the increase in the MMR in the Netherlands and Sweden in the late 1920s and early 1930s was the result of an increase in deaths from septic abortion superimposed on a more or less constant rate of deaths from puerperal fever.
Unlike deaths from septic abortion, those from puerperal fever were largely preventable. The risk of puerperal infection, however, was much greater in the past than it is today because of the prevalence and virulence of the organism known as the B- hemolytic streptococcus, Lancefield group A {Streptococcus pyogenes), which was responsible for the vast majority of deaths from puerperal fever. Before the Second World War, this organism was frequently carried in the nose or throat of a large proportion of the healthy population (“asymptomatic carriers”). It was also common not only as the cause of scarlet fever and erysipelas, but as an infection in people suffering from such minor complaints as sore throats, whitlows, and minor abrasions, so that the risk of cross-infection was high. The prevalence of the virulent streptococcus and the inadequacy of antiseptic procedures contributed to the high MMR. Today, asymptomatic carriers are rare, scarlet fever has become a minor disease, and rheumatic fever and acute nephritis have virtually disappeared. The reasons for the change are uncertain.
Deaths from toxemia (eclampsia and preeclampsia) accounted for about 20 to 25 percent of total maternal deaths and hemorrhage (antepartum and postpartum) for about 20 percent. Each of the remaining causes, such as “white leg” (deep-vein thrombosis) and embolism, ruptured uterus, ectopic pregnancy, hyperemesis gravidarum, puerperal mania, and so on, contributed 5 percent or less to the total.