HEART disease is estimated to complicate one to four per cent of pregnancies. The occurrence of heart disease in pregnancy is associated with an increased risk of complications and an increased risk of mortality not only during pregnancy but also up to one year post-partum.

The epidemiology of heart disease in pregnancy has been changing and its importance as a complicating factor during pregnancy has been increasing. Heart disease is frequently not diagnosed prior to pregnancy and late diagnosis has been associated with an increased risk of complications and mortality.

Causes of cardiac disease in pregnancy

All forms of cardiac disease can be seen in the pregnant female. The relative frequency of congenital heart disease in the young means that worldwide this is the most common cause that is seen particularly in high-income countries (HICs). In low- and middle-income countries (LMICs) which have a high prevalence of rheumatic fever and subsequent heart valve disease. Rheumatic heart disease can be seen more frequently and may be the predominant cause as opposed to congenital heart disease. This has been noted particularly in much of the African continent and Latin America. Recently there has been a rise in prevalence of chronic non-communicable diseases (hypertension, diabetes, hyperlipidemia, obesity) and the rise in age at which women are becoming pregnant. These factors have resulted in a rise in the rates of lifestyle-related cardiac disease during pregnancy. This increase has been noted in both HICs and LMICs.

Importance of cardiac disease in pregnancy

Cardiac disease in pregnancy is important because it is associated with an increase in complications and in the risk of death during and after pregnancy. Studies have demonstrated that cardiac disease in pregnancy is associated with an increased risk of hospitalisation, admission to intensive care, increased risk of foetal loss and maternal mortality. It is important to note that while much of the risk is noted during late pregnancy and delivery, a significant amount of morbidity and death occurs up to one year after pregnancy. The above is important from the point of view of the individual pregnant female but there are, however, important implications for the public health system.

The preventable death of pregnant females has been recognised as an important problem and indeed one of the World Health Organization’s (WHO’s) Millennium Development Goals is the lowering of maternal mortality worldwide. Improvement in obstetric care particularly in LMICs has led to lower pregnancy-related mortality in many countries including Jamaica. However, as we note a reduction in the complications/mortality that are related directly to pregnancy there has been an increase in complications and mortality that can be attributed to chronic non-communicable disease. The rise in chronic non-communicable disease in combination with the increasing ages at which women are becoming pregnant has led to an increase in the incidence of lifestyle-related heart disease in the pregnant female. These include hypertensive heart disease, coronary artery disease and cardiomyopathies. When compared to pregnant patients with congenital heart disease these patients have more complications and a higher risk of dying during and after pregnancy.

The effect of the increasing incidence of these lifestyle-related heart diseases in the pregnant female is quite variable. The United States is unique among HICs in that it has been experiencing an increase in maternal mortality with cardiac and vascular disease being the most common cause. Many other HIC’s have stable or decreasing maternal mortality; however, the fall in the complications and mortality from obstetric causes often masks the rising morbidity and mortality from cardiac and vascular causes. This pattern is mirrored in many LMICs where a rapid increase in chronic non-communicable disease is associated with cardiac and vascular disease that impacts the pregnant female. Given the high rates of obstetric complications in these countries the relative contribution of morbidity and mortality from chronic non communicable disease is lower, but it is likely that in coming years and decades this will be an increasingly recognised as a major problem.

A critical issue for the women with cardiac disease in pregnancy is the excess morbidity and mortality that accompany late diagnosis. A delay in diagnosis has been associated with an increased risk of complications and increased risk of maternal death. This delay in diagnosis has been noted both in HICs such as the United Kingdom and the United States and many LMICs. Studies have found that diagnosis is sometimes made during labour and post-partum period. One review from the United States found that a significant amount of maternal death demonstrated to be cardiac was diagnosed during autopsy.

Challenges in diagnosis

The diagnosis of cardiac disease in pregnancy can be quite challenging. Clearly some women will be known to have heart disease prior to becoming pregnant. In these cases, algorithms for management exist and clinical care is dictated by the type and severity of the heart disease present. For some conditions such as congenital heart disease with elevated pressures in the lung or severe weakness of the muscle of the heart, pregnancy is contraindicated, and abortion may be considered. In other conditions, a normal pregnancy is possible with close monitoring by cardiac medicine and obstetrics. On occasion, medical or surgical interventions may be required for a safe pregnancy.

The major clinical dilemma occurs when cardiac disease exists prior to pregnancy that has not been diagnosed or the patient develops heart disease while pregnant or immediately after pregnancy. Unfortunately, many of the symptoms of cardiac disease are seen in normal pregnancy including shortness of breath, swelling of the legs, dizziness, exertional intolerance, etc. It can be difficult to decide whether the patients’ symptoms are normal for pregnancy or are reflective of abnormalities of the cardiovascular system. This difficulty has increasingly been recognised and algorithms are being developed to improve the accuracy of diagnosis. Generally, however any suspicion of cardiac disease in a pregnant female requires ultrasound evaluation of the heart and cardiology evaluation as an urgency. Studies have suggested that there is the is the opportunity for earlier diagnosis with potential improvement in outcome.

Data from Jamaica published in the British Journal of Obstetrics and Gynaecology in 2015 by Professor Affette McCaw Binns et al found that the there was an increasing contribution of non-communicable diseases to maternal mortality in Jamaica from 1998 to 2015. They also noted that of non-obstetric causes of maternal death 56 per cent was related to rheumatic heart disease and stroke.

What can I do to lower my risk?

Heart disease in pregnancy is a significant medical problem. However, with cardiac disease affecting less than four per cent of pregnancies, this is uncommon. With the increasing prevalence of chronic non-communicable diseases, it is likely that this will continue to be a problem in the future. Given these findings, young females who are thinking about conceiving should be following a healthy lifestyle to lower the risk of chronic disease. If you are known to have heart disease and are thinking of becoming pregnant, visit a cardiologist for an assessment of the safety and outcome of pregnancy for your cardiac specific condition. For both women with and without heart disease who are pregnant, early, and regular antenatal care should be sought. During the antenatal period discuss any unusual symptoms with your obstetric provider. Early echocardiography and cardiac consultation should be performed if there is any suspicion of cardiac disease especially in those with family history or advanced maternal age.

Dr Ernest Madu, MD, FACC and Dr Paul Edwards, MD, FACC are consultant cardiologists for Heart Institute of the Caribbean (HIC) and HIC Heart Hospital. HIC is the regional centre of excellence for cardiovascular care in the English-speaking Caribbean and has pioneered a transformation in the way cardiovascular care is delivered in the region. HIC Heart Hospital is registered by the Ministry of Health and Wellness and is the only heart hospital in Jamaica. Correspondence to info@caribbeanheart.com or call 876-906-2107