17.4 Heart failure in pregnancy

Where obstetric care is good, and the more easily preventable causes of maternal mortality have been eliminated, death from heart disease is one of the important remaining reasons why mothers die. Primary Mother Care warns staff in the antenatal clinic to be on the look out for mothers with heart disease, which usually presents as a cough, dyspnoea on exertion or at rest, malaise, oedema, or palpitations. Only rarely will a mother know that she has heart disease. It is most commonly due to anaemia, rheumatic carditis, or congenital heart disease. Fortunately, provided she is properly cared for, pregnancy does not influence the long-term outcome of her heart disease. One of the dangers is that she may suddenly go into failure, with little warning, in the last weeks of pregnancy, while in labour, or in the puerperium; so watch her carefully and treat her early.

Obstetrically, mothers with heart disease fall into these four groups:

Group One

Mothers with heart disease, but no limitation of their physical activity.

Group Two

Mothers with slight limitation of physical activity. They are comfortable at rest, but ordinary activity fatigues them and makes them short of breath.

Group Three

Mothers who have marked limitation of their physical activity and are comfortable at rest, but less than ordinary activity gives them symptoms. They may show signs of heart failure.

Group Four

Mothers who cannot do any physical activity without discomfort. They have symptoms at rest, obvious signs of heart failure, and any activity makes them worse. They are less likely to become pregnant, but if they do, delivery by any method may kill them.

The diagnosis of heart disease can be difficult, because systolic murmurs, oedema, and dyspnoea are common in normal pregnancy. Base your diagnosis of significant heart disease on: (1) Obvious cardiac enlargement. (2) Diastolic, presystolic, or continuous heart murmurs. (3) A harsh, loud, systolic murmur, especially if there is also a thrill. (4) Serious arrhythmia. (5) Signs of congestive failure—a raised jugular venous pressure, basal crepitations, ankle oedema, and an enlarged liver.