Cardiac disease is the leading medical cause of material death during pregnancy in the United Kingdom.1 Due to recent advances in cardiac surgery and congenital heart disease, the butter is now the most common subtrate of heart disease in pregnancy in the western world.2 The combination of cardiac disease and pregnancy carry mortality and morbidity risks such as heart failure, thromboembolism, and cardiac arrhythmia. Furthermore, fetal and neonatal adverse events, including intrauterine growth restriction, premature birth, intracranial haemorrhage, and fetal loss are relatively common. Prepregnancy counselling (Table), including advice on contraception, and optimal care during pregnancy is, thus, becoming a major topic in current cardiologic and obstetric practice.
The first task is to asses the risks of pregnancy for the mother. Pregnancy is associated with profound changes in peripheral resistance, cardiac output, and blood volume, in order to provide appropriate uterine blood flow. In the first trimester of pregnancy, the blood pressure falls secondary to a drop in peripheral vascular resistance. Thereafter, plasma volume increases by 25%, and this change in volume is associated with an accelerated heart rate and a 50% increase in cardiac output. Blood pressure starts to rise in the beginning of the third trimester. Structural changes to the heart and great vessels also occur and include myocardial hypertrophy, chamber enlargement, and valvular regurgitation.3-11 These major cardiovascular changes may, in women with cardiac disease, be poorly tolerated and precipitate heart failure and clinical decompensation. Proarrhythmic effects and an increased likelihood of thrombosis could also compromise these patients.12
Labour and delivery is a particularly risky period. Their timing is crucial to balance maternal and neonatal morbidity, and mortality risks. A clear management plan should be established in advance and be communicated to all parties involved, including the patient. In general, vaginal delivery under epidural anaesthesia is preferable; it carries a lower risk of complications for both the mother and the fetus compared to caesarean section, namely lower risk of haemorrhage, infection, and thrombosis. But every case should be considered individually, taking into account not only obstetric and cardiac factors but also availability of the multidisciplinary team required. Large units are more likely to offer round the clock coverage, compared to smaller units; the latter may, therefore, need to utilize more caesarean section for scheduling purposes.
The risk of maternal death during pregnancy varies and has been reported to be as high as 30%-50% for patients with pulmonary hypertension.13,14 In contrast, mortality and morbidity risks are very small in patients with mild or repaired lesions and, in such cases, appropriate reassurance should be provided and local obstetric and cardiac care should suffice. While Siu et al5,6 and a recent meta-analysis from the Netherlands15 have provided important data on maternal morbidity and mortality, when it comes to the individual patient with congenital heart disease other features than the lesion itself, previous surgery and generic cardiac risk factors such as age, physical status, and smoking play also a role (Table 1).
The essence of preconception counselling is that it needs to be multidisciplinary, in good time (ideally in teenage years) and the limitation of existing data that guide us, the physicians, need to be discussed with the patient and the family. Furthermore, the uncertainty of the potential adverse effects of pregnancy on ventricular function needs to be acknowledged.16 Young female patients with valvular lesions should be taught not to accept metalic prostheses, before previous specialist consultation, as the need for anticoagulation will complicate significantly future pregnancy and increase maternal or neonatal risks (depending on the anticoagulation chosen).17 Nevertheless, when the individual patient decides to proceed with pregnancy or presents pregnant to us, all efforts should be made to minimize risks involved. To achieve this objective a multidisciplinary approach, additional resource allocation, and great attention to detail are all essential.8,18
Manso et al19 in this issue of the journal report their experience on pregnancy outcomes amongst 56 women with congenital heart disease. Severity of congenital heart disease had an impact on both maternal and neonatal outcomes. The authors should be congratulated for their multidisciplinary approach towards this new challenge and for the opportunities that derive both for health care professionals as well as patients with congenital heart disease. Congenital heart disease is the most common congenital defect (approximately 1% of newborns are affected around the world). At least 85% of patients with congenital heart disease now survive to adulthood and half of them are women, most of reproductive age. Their natural desire is to have their own children. We, cardiologists, clearly need to work closer with our obstetric and anaesthetic colleagues, understand better the impact of pregnancy on long-term cardiovascular outcome, and communicate at greater extent this emerging data with health care professionals and our patients, so that we can help every single patient with congenital heart disease reach their full life potential.
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Dr Peset received funding support from the Spanish Society of Cardiology. Professor Gatzoulis and the Royal Brompton ACHD Programme had received support from the British Heart Foundation.
Correspondence:
Prof. M.A. Gatzoulis, Royal Brompton Hospital, Sydney Street, London 6NP SW3, UK
E-mail: M.Gatzoulis@rbht.nhs.uk