Epidemiology
Cardiac disease in pregnancy is becoming more common. There are several reasons for this:

Due to better care, women with congenital cardiac disease are surviving to reproductive age.

Changes in demography have also resulted in an increase in incidence in areas where there are large immigrant communities. One study in West London found that of 139 women referred for evaluation of a heart murmur in pregnancy, 97% were found to have a physiological murmur and only four patients had significant new conditions.
Three out of the four women were immigrants with no previous history of heart disease.

The tendency to postpone motherhood until the third decade is having an effect.

The report of confidential enquiries into maternal and neonatal deaths in the UK 2006-2008 reported a total of 53 deaths due to heart disease in pregnancy.[4] The number in the previous triennium was 48. The rate for indirect maternal deaths was 6.72/100,000 pregnancies and, within that, the rate for cardiac disease was 2.31 per 100,000 maternities.
Therefore, cardiac disease is the most common cause of indirect maternal death and the most common overall cause of death.

Risk factors

Risk factors for heart disease in pregnancy include:

A positive family history of inherited cardiac disease.
Hypertension.
Obesity.
Increased age.
The last factor listed above is becoming important as more women in older age groups seek assisted conception.

Aetiology
Sudden arrhythmic death syndrome (SADS) was the most common cause of maternal cardiac death in 2006-2008 (10 deaths), closely followed by cardiomyopathy (9 deaths).

Other leading causes :
were aortic dissection, ischaemic heart disease and myocardial infarction. Deaths from pulmonary hypertension and from congenital heart disease continue to decrease.
The last 50 years have seen a dramatic reduction in rheumatic heart disease but it is still seen in immigrant communities and in developing countries. However, there were no deaths from rheumatic heart disease in this last triennium.

What to look for at booking or later in pregnancy
The recommendations of the last Centre for Maternal and Child Enquiries (CMACE) report state that:[

“There must be a low threshold for further investigation of pregnant or recently delivered women who complain of chest pain that is severe, or radiates to the neck, jaw or back, or is associated with other features such as agitation, vomiting or breathlessness, tachycardia, tachypnoea, orthopnea or acidosis. This is especially important for women who smoke, are obese or who have hypertension.”

History

The following should be discussed at the booking clinic:

A past history of congenital or acquired heart disease.
A family or personal history of congenital heart disease.
A history of hypertension.
A history of breathlessness, fatigue, or oedema.

G Mohan