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................................................................................................................................................................ cardiology ward, and also at the emergency department, ICU, and obstetric ward, and should be used with a low threshold. During pregnancy, some changes in echo parameters are expected, such as mild dilatation of the chambers, a change in LV wall thickness, and an increase in valve gradient.34,52 Transoesophageal echocardiography is relatively safe; however, the risk of vomiting/aspiration and sudden increases in intra-abdominal pressure should be considered, and foetal monitoring performed.

3.4.3 Exercise testing Physiological exercise testing is an integral part of follow-up in adult congenital heart disease and valve disease,29,53 and should be performed in patients with known heart disease who plan pregnancy. This Task Force recommends submaximal exercise testing (80% of predicted maximal heart rate) in asymptomatic patients with suspected heart disease if already pregnant. There is no evidence that it increases the risk of spontaneous miscarriage.30 Stress echocardiography using bicycle ergometry may improve diagnostic specificity.54 Dobutamine stress is rarely indicated during pregnancy and, because pregnancy in itself is a stress test, its use should be avoided when other options are available.

3.4.4 Ionizing radiation exposure The potential risks of ionizing radiation exposure to the foetus depend on the stage of pregnancy and the absorbed dose. Risks are highest during organogenesis and the early foetal period, less in the second trimester, and least in the third trimester.55 Malformations are typically associated with the central nervous system. Early in pregnancy (including 0–8 days pre-implantation), the high incidence of spontaneous abortion makes the evaluation of radiation-induced pre-natal death difficult, although it occurs at other stages of gestation with doses >250 mGy. Observed radiation-induced abnormalities (typically at doses of 100–200 mGy) include growth restriction, intellectual disability, malignancies, and neurological effects.56,57 The periods of greatest vulnerability include growth retardation at 8–56 days, microcephaly at 14–105 days, and intellectual deficit/seizures/severe mental impairment at 56–105 days.58 An increased risk of childhood cancer with in utero doses of approximately 20 mGy has been reported, with an estimated 1–2 cases of childhood cancer occurring per 3000 children exposed to 10 mGy of radiation in utero.59 If possible, procedures should be delayed until at least the completion of the period of major organogenesis (>12 weeks after menses). All medical radiation doses must be kept ‘as low as reasonably achievable’. If ionizing radiation is required, risks and benefits should be communicated to the mother, and informed consent obtained. The radiation dose to the foetus should be kept as low as possible (preferably <50 mGy) with clear documentation, particularly if the foetus is in the field of view (see section 3.7.1).

3.4.5 Chest radiography and computed tomography Although the foetal dose from chest radiography is <0.01 mGy, it should only be performed if other methods fail to clarify the cause of symptoms. Lung ultrasound is a promising alternative imaging modality, although its use in pregnancy has yet to be clarified. CT is usually not necessary for cardiac disease during pregnancy and is not recommended, except for the diagnosis or exclusion of pulmonary embolism (PE) or aortic pathology where other diagnostic tools are insufficient (section 10), and where low radiation CT with 0.01–0.66 mGy can be used.53,60

3.4.6 Cardiac catheterization Cardiac catheterization is seldom needed for diagnostic purposes, but can be necessary to guide interventional procedures. The mean radiation exposure to the unshielded abdomen is 1.5 mGy, and <20% of this reaches the foetus. For example, successful closure of a patent foramen ovale was achieved with the Helex device in three patients in the second trimester. Radiation doses, as assessed by dose area product, were 260, 58, and 19 cGy/cm2, with estimated uterine (foetal) doses of <0.005, <0.001, and <0.0005 mGy, respectively.61 The radial approach by an experienced operator is preferable. Most electrophysiological studies should only be performed if arrhythmias are medically refractory and cause haemodynamic compromise. Electroanatomical mapping systems should be used to reduce the radiation dose (section 3).

3.4.7 Magnetic resonance imaging MRI is advised if other non-invasive diagnostic measures are not sufficient for definitive diagnosis, and is preferred to ionizing radiationbased imaging modalities when possible.53,55 Evidence regarding gadolinium-based contrast in pregnancy is controversial and its use should be avoided if possible, especially in the first trimester. Excretion of gadolinium-based agents into breast milk is limited [<0.04% of an intravenous (i.v.) dose within the first 24 h, with 1–2% absorption].62 Data suggest that it is safe to continue breastfeeding after the administration of such agents.

3.5 Genetic testing and counselling

The risk of inheriting cardiac defects is raised significantly in comparison with parents without CVD, where the risk is approximately 1%.63,64 Heritability varies between 3 and 50% depending on the type of parental heart disease. Children of parents with an autosomal dominant condition [e.g. Marfan syndrome, hypertrophic cardiomyopathy (HCM), or long QT syndrome (LQTS)] have an inheritance risk of 50%. The final phenotype will also be determined by incomplete penetrance and pleiotropic effects, and may vary significantly.65 For defects that are inherited in a polygenic manner, recurrence risk is less clearly defined. Genetic testing in cardiomyopathies is not appropriate for pre-natal diagnosis in dilated cardiomyopathies, except for selected disorders or high-risk situations in the setting of expert teams after detailed clinical and family assessment.66 In patients with venous thrombo-embolism (VTE), genetic testing is considered to be justified only for relatives of probands with a deficiency of natural anticoagulants or after recurrent VTEs.67 Downloaded from academic.oup.com/eurheartj/article/39/34/3165/5078465 by guest on 07 October 2026