Introduction

Most medical diseases increase in prevalence with age. The average age of childbirth is rising in the UK, with the proportion of maternities in women aged 35 years or over increasing from 8% in 1985 to 19% in 2005, and continuing to rise. Over the same period, the proportion of maternities in women aged 20—29 years fell from 64% to 44% (Figure 14.1). As women delay pregnancy until their 30s and 40s, more will embark on pregnancy with a pre-existing medical disorder. As the number of older pregnant women increases, more can also be expected to have a medical disorder diagnosed during pregnancy, increasing the requirement of specialist input and resources to care for them effectively.

Mortality statistics reveal that the main causes of death in women of childbearing age are cancer, circulatory diseases (mainly ischaemic heart disease and stroke), accidents and respiratory disease, with all except accidents increasing with age. It can therefore be expected that these illnesses will become more prominent in maternal mortality statistics. Indeed, cardiac disease is now the most common cause of maternal death in the UK.

The Confidential Enquiries into Maternal and Child Health (CEMACH) have been collecting data on maternal deaths in the UK since 1952. The trends show that maternal mortality has fallen dramatically since then. However, since the 1991—93 period, the total maternal mortality has increased slightly and indirect deaths (which are mainly due to underlying medical or psychiatric causes) have become more frequent than direct deaths (which are related to pregnancy itself).