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............................................................................................................................................................................. 6. Valvular heart disease

At childbearing age, valvular heart disease is often due to rheumatic heart disease, particularly in low–middle-income countries. Mechanical valve prostheses raise specific problems during pregnancy.92,195,196 Risk assessment and management need to consider the resources available in high- and low–middle-income countries. The current background information and detailed discussion of the data for the following section of these Guidelines can be found in ESC CardioMed.

6.1 Stenotic valve lesions

In stenotic valve diseases, increased CO causes an increase in transvalvular gradient of 50%, mainly between the first and second trimesters,197 which increases the risk of maternal and foetal complications.29,42,198

6.1.1 Mitral stenosis 6.1.1.1 Maternal risk Mild mitral stenosis (MS) is generally well tolerated.198,199 HF occurs in one-third of pregnant women with a valve area <_1.0 cm2 and in onehalf of those with a valve area <_1.5 cm2,199 most often during the second trimester, even in the absence of symptoms before pregnancy.198 Sustained AF, although rare (<10%), may precipitate HF and thromboembolic events.199,200 Mortality is between 0–3% in western countries198–200 and higher in low–middle-income countries.201,202 NYHA class >_ II, systolic PAP >30 mmHg, severe stenosis, and older age are associated with maternal complications.199

6.1.1.2 Obstetric and offspring risk The risk of acute HF peripartum depends on symptoms and PAP.194 Prematurity rates are 20–30%, intrauterine growth retardation 5–20%, and foetal death 1–5%.198–200,203 Offspring risk is higher in women in NYHA class III/IV during pregnancy.29,194

6.1.1.3 Management

Diagnosis. MS is considered clinically significant if valve area is <_1.5 cm2.204,205 The reference measurement of MS severity is planimetry; Doppler-derived pressure half-time is less reliable but can be used during pregnancy.204,205 Mean gradient and PAP assess haemodynamic consequences and prognosis.204,205 The assessment of mitral anatomy and associated regurgitation is important when percutaneous mitral commissurotomy is considered.204,205 Before pregnancy, exercise testing is useful to assess objective exercise tolerance and exercise echocardiography may provide additional information.

Medical therapy. When symptoms or clinically significant PH (echocardiographically estimated systolic PAP >_50 mmHg) develop, activity should be restricted and beta-1-selective blockers (preferably metoprolol or bisoprolol) commenced.5 Diuretics may be used if symptoms persist, avoiding high doses (see table ‘Recommendations for drug use in pregnancy’).5 Anticoagulation using UFH, LMWH, or vitamin K antagonist (VKA), according to the context and term, is recommended in the case of paroxysmal or permanent AF, left atrial thrombosis, or prior embolism.5 Anticoagulation should be considered in women in sinus rhythm with significant MS and spontaneous echocardiographic contrast in the left atrium, large left atrium (>_ 60 mL/m2), or congestive HF. Interventions. All patients with significant MS should be counselled against pregnancy and intervention should be considered prepregnancy, favouring percutaneous intervention, even if asymptomatic, and even more so if the valve area is <1.0 cm2.198,204

During pregnancy, percutaneous mitral commissurotomy is preferably performed after 20 weeks of gestation. It should only be considered in women with NYHA class III/IV and/or systolic PAP >_50 mmHg, despite optimal medical treatment in the absence of contraindications (see table ‘General Recommendations’).204 Closed commissurotomy remains an alternative in low–middle-income countries. Due to foetal risk, open-heart surgery should be reserved for cases in which all other measures have failed and the mother’s life is threatened.206

Follow-up during pregnancy. Clinical and echocardiographic follow-up is indicated monthly or bimonthly depending on haemodynamic tolerance. In mild MS, evaluation is recommended every trimester and prior to delivery.

Labour and delivery. Vaginal delivery should be favoured in patients with mild MS, and in patients with significant MS in NYHA class I/II without PH. Caesarean section is generally considered in patients who are in NYHA class III/IV or have PH, or in whom percutaneous mitral commissurotomy cannot be performed or has failed.

Follow-up and prognosis after delivery. Close monitoring is needed in the days following delivery. Late prognosis depends mainly on the risk of stenosis progression or re-stenosis after commissurotomy, and justifies regular follow-up.204

6.1.2 Valvular aortic stenosis The main cause of AS is bicuspid aortic valve followed by rheumatic heart disease.

6.1.2.1 Maternal risk Cardiac morbidity is related to the baseline severity of AS and symptoms.207 HF is rare (<10%) in women with moderate AS and in those who were asymptomatic before pregnancy, while it occurs in one out of four symptomatic patients.207 Even in patients with severe AS, pregnancy is often well tolerated if prior exercise tolerance was normal. Mortality is now rare if careful management is provided.194,198,207–209 Arrhythmias are rare.206 Women with bicuspid aortic valve have a low-risk of aortic dissection if the aortic diameter is <50 mm (section 5.2).

6.1.2.2 Obstetric and offspring risk Obstetric complications may be increased in patients with severe AS.207,209 Pre-term birth, intrauterine growth retardation, and low birth weight occur in 20–25% of the offspring of mothers with moderate and severe AS, and are increased in severe AS.207 Miscarriages and foetal death rates are <5%. The risk of genetic transmission of LV outflow tract malformations justifies the performance of foetal echocardiography in AS due to bicuspid aortic valve.5

6.1.2.3 Management

Diagnosis. The severity of AS is assessed by combining flowdependent indices and valve area.204,205 Exercise testing is recommended in asymptomatic patients before pregnancy to evaluate Downloaded from academic.oup.com/eurheartj/article/39/34/3165/5078465 by guest on 07 October 2026