MATERNAL MORTALITY

A maternal death is defined by the International Classification of Diseases, Injuries and Causes of Death (ICD-10) as the death of a woman while pregnant or within 42 days after abortion, miscarriage or delivery that are due to direct or indirect maternal causes. These deaths are divided into direct, indirect, late and incidental (Box 25.1). The maternal mortality rate is the number of such deaths per 100 000 maternities.

Box 25.1 Definitions of maternal deaths

International Classification of Diseases (ICD-10): Deaths of women while pregnant or within 42 days of delivery, miscarriage or termination of pregnancy irrespective of the cause of death.

World Health Organization (WHO): Death of a woman during pregnancy, childbirth or in the 42 days of the puerperium irrespective of the duration or site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management. Excludes incidental deaths from causes unrelated to pregnancy such as death from injury or malignancy.

Direct: Deaths resulting from obstetric complications of the pregnant state (pregnancy, labour and puerperium), from interventions, omissions, incorrect treatment or from a chain of events resulting from any of the above.

Indirect: Deaths resulting from previous existing disease or disease developed during pregnancy and which was not due to direct obstetric causes, but was aggravated by the physiological effects of pregnancy. Includes deaths consequent on psychiatric disease, suicide and homicide.

Late: Deaths occurring between 42 days and 1 year after termination of pregnancy, miscarriage or delivery that are due to direct or indirect maternal causes.

Incidental: Deaths from unrelated causes which happen to occur in pregnancy or the puerperium, e.g. passenger in a motor vehicle accident.

In most developed countries the maternal death rate remained about the same from 1850 to 1934, when it began to fall. In the period before the mid-1930s it was about 500 per 100 000; by the mid-1980s, in many industrialized countries it had fallen to fewer than 10 per 100 000 maternities (Fig. 25.1). The initial fall was due to the control of infections by better obstetric care and the introduction of antibiotics. The second factor was that most women availed themselves of good-quality antenatal care, which enabled complications to be detected early and treatment to be offered, usually in well-equipped hospitals staffed by trained medical attendants. Blood became increasingly and quickly available from blood banks, which considerably reduced the deaths due to haemorrhage. Sociological changes have also occurred in the past 60 years: fewer women now have more than three children, and most have their pregnancies before the age of 35. Higher parity and advancing age increase the risk of maternal death. There has been a small rise in the maternal mortality rates in some developed countries in the last decade. Whether this is due to women with medical conditions that previously precluded pregnancy having children, increasing maternal age, the rise in obesity or better ascertainment of cases is not clear.