Traditionally, the analysis of maternal deaths has been the criterion of choice for evaluating women's health and the quality of obstetric care.
Due to the success of modern medicine such deaths have become very rare in developed countries, which has led to an increased interest in analyzing so-called "near miss" events.
[2] The small number of cases makes the evaluation of maternal mortality practically impossible[2][3] Historically, the study of negative outcomes have been highly successful in preventing their causes, this strategy of prevention therefore faces difficulties when if the number of negative outcome drop to low levels.
In the UK, for example, the most dramatic decline in maternal death was achieved in Rochdale, an industrial town in the poorest area of England.
In 1928 the town had a Maternal Mortality Ratio of over 900 per 100,000 live births, more than double the national average of the time.