Promising perspectives on pregnancy in women with congenital heart disease

This editorial refers to ‘Maternal and neonatal complications in women with congenital heart disease: a nationwide analysis’, by A.E. Lammers et al., https://doi.org/10.1093/eurheartj/ehab571. With the increasing survival of children born with congenital heart disease into adult age, the focus has shifted from survival to quality of life. Most patients wish to live a normal life, including participation in sports and also starting a family. In earlier times, concerns were raised about the risks of pregnancy, as pregnancy is associated with impressive hormonal changes and haemodynamic impact. Older studies reported high rates of maternal complications, including maternal mortality, and substantial rates of perinatal complications.1–3 In addition, there were concerns about the hereditable recurrence risk of congenital heart disease for the baby. However, studies were limited by small sample size or retrospective study design, and for a long time only the reported data from Nora and Nora were available.4 As a result, many physicians and, thus patients, were reluctant to embark on pregnancy, especially in more complex congenital heart disease, such as women with a systemic right ventricle, but also in severe aortic stenosis. The risks were deemed very high or too high, and these women were typically advised against pregnancy. Although research in the field of pregnancy and congenital heart disease is hampered by small numbers, often with retrospective design, over the past decades gradually some larger studies and registries became available, elucidating the risks of pregnancy and in fact showing relatively good results. A clear development over time in adult patients with congenital heart disease (ACHD) was seen for instance in women with transposition of the great arteries corrected with the Mustard and Senning operation, which started as being seen as very high risk, to high risk, and now to moderate risk. The trend for women with aortic stenosis is now also to allow pregnancy, even when the stenosis is severe, as long as the woman is asymptomatic.5–7 The study of Lammers et al. in this issue of the European Heart Journal provides an important contribution to the existing literature.8 Not only is this the largest study, but it includes all women with ACHD, without a possible bias of only including patients seen at a tertiary centre or including patients with other kinds of heart disease. Furthermore, because it is performed in a western country with an optimal healthcare system, the results are applicable to other western countries with comparable systems of care organization with appropriate counselling in place and good collaboration between cardiac and obstetric care. The pregnancy outcomes in studies with a global perspective, including patients from developing countries, show less favourable results (Graphical Abstract).8,9 These differences illustrate how the healthcare system and environment of women have great impact on their pregnancy outcomes and show that we still need to work to improve these outcomes for all women worldwide.10 A possible step forward is to utilize the expertise in the specialized healthcare centres such as described by Lammers et al., by providing long-distance digital or telephone consultations to rural centres in developing countries. Lammers et al. also describe better pregnancy outcomes than an older study (1980–2007) in a Dutch and Belgian healthcare system similar to the German system, which may be due to advances in medical care for both the treatment of the original heart defect in the mother, and the management of pregnancy in heart disease, which includes the introduction of multidisciplinary pregnancy heart teams and the establishment of international guidelines (Graphical Abstract).8,11 Comparison of studies on pregnancy outcomes of women with congenital heart disease. ACHD: adult congenital heart disease. Comparison of studies on pregnancy outcomes of women with congenital heart disease. ACHD: adult congenital heart disease. The most important finding of this well-performed and excellently written study is the zero maternal mortality in women with congenital heart disease.8 This is unexpected and fantastic news. As the authors point out, this is partly the result of good counselling, where the high-risk patients were advised against pregnancy and most probably did not become pregnant. However, other studies show that some women at highest risk (mWHO IV) will actually still become pregnant, irrespective of counselling. In any case, this important finding makes it possible to reassure the large majority of ACHD patients about the mortality risk of pregnancy. This is an important message and should lead to a change in policy from approaching pregnancy as potentially very dangerous, to considering pregnancy as relatively safe and explaining the possible risks, on the condition that women in mWHO IV should not become pregnant. Of course morbidity is increased, but the rates are relatively low. The prevalence of heart failure in pregnancy might be under-reported in the study of Lammers et al., because pregnancies in women who had heart failure in the year before the pregnancy were not considered to be complicated by heart failure, probably because of the limitations of the method of registration with ICD codes. The relationship between the occurrence of stroke and having a co-existent atrial septal defect or patent foramen ovale is shown nicely and should lead to a more proactive approach in taking lifestyle measures and considering a low threshold to prescribing antiplatelet drugs in these women. As in other studies, the mode of delivery is more often by Caesarean section in women with congenital heart disease, while this is not advised in the latest guidelines.6 An attempt must be made to change this policy, because planned Caesarean section in women with heart disease does not improve maternal outcome over vaginal delivery and can be harmful for neonatal outcome.12 Another important finding of this study is the relatively high risk of the baby also having congenital heart disease.8 This study provides data on the numbers of children needing cardiac surgery with the use of cardiopulmonary bypass at young age, as a nice surrogate marker for congenital heart disease needing treatment, and reports 6% in ACHD patients vs. 0.4% in the general population. Scarce data were available on this topic, and for many years we had to rely on old studies.4 In particular, the comparison with the age-matched control group in this study provides the opportunity to finally gain reliable estimates. In counselling we can now inform our patients that the risk for their baby to also have congenital heart disease requiring surgery within ≤6 years is ∼15 times higher, compared with the general population (6% vs. 0.4%).8 What is astonishing is the reported rate for a univentricular heart being as high as 26.5%. Until now there was no reliable information on this specific congenital defect, because most women did not have children. However, this high rate fuels the discussion on pregnancy for women after Fontan correction. In addition to the high rates of miscarriage and maternal and foetal complications and the fear of the long-term impact on the maternal condition, now the high rate of foetal congenital defects also has to be taken into account when deciding on pregnancy in these high-risk women. It would be of interest to study trends over time, as earlier and better prenatal diagnostics and changes in termination management might have an impact, not only in these complex defects but also in less complex cardiac defects. In conclusion, the study by Lammers et al. is an excellent and clinically relevant contribution to the existing literature on pregnancy in women with congenital heart disease. The study shows that a good healthcare system, a multidisciplinary approach, and decisive pre-pregnancy counselling are effective in achieving safe pregnancies. Pre-pregnancy counselling with an individualized approach is a crucial step in this process, because both maternal and perinatal outcomes vary greatly by the complexity of maternal illness, and further studies dedicated to specific congenital diagnoses remain warranted. Conflict of interest: none declared. The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology.