**11. Pregnancy**

Although, the vast majority of pregnancies with congenital AS go through labour uncompli‐ cated, some pregnancies with severe AS have a higher risk rate of morbidity, although the mortality rates still remains rare [126, 127].

Severe AS is not well tolerated in pregnant women and is associated with high peripartum complications [75]. Around one-third of the pregnant women with maternal congenital AS showed clinical complications with a significant rate of abortion [128]. Of note, it is recom‐ mended that women with AS who are considering becoming pregnant receive prepregnancy counselling [39].

ease, it seems that BAV disease is linked with both genetic predisposition and defects in the early valvulogenesis. Further investigation is required with respect to the basic genetic and embryological defects associated with BAV disease and the proximal aortic dilatation in‐ cluding the cellular mechanisms and signalling pathways. This will give us more under‐ standing regarding the background of the degeneration and calcification of the bicuspid valve, and the development of aortic aneurysm. This could offer new pharmacological tar‐

Bicuspid Aortic Valve

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The dilatation of the proximal thoracic aorta may lead to complications including ascending aortic aneurysm and dissection. Early detection, vigilant patient assessment and frequent follow-up by imaging including echocardiography, CT and CMRI can potentially persevere

Several interventional options are available for patients with BAV disease and aortic dilata‐ tion. Balloon valvuloplasty is indicated in young adults and adolescents without significant‐ ly BAV calcification. Surgical repair (Yacoub and David procedure) should be considered when BAV disease is presented without any significant signs of calcification or valve thick‐ ening. In contrast, when calcified BAV disease is present, AVR, Bentall procedure or Ross procedure is necessary. Although in some cases these procedures are performed in valves without calcification. TAVI is relatively contraindicated due to the asymmetric anatomy which is observed patients with BAV disease. The TAVI device could potentially be affected to a noncircular expansion with the risk of paravalvular leak. BAV patients were excluded

Despite the fact that limited data exist with respect to prophylactic interventions, BAV dis‐ ease associated aortic dilatation with absence of additional risk factors and co morbidities is indicated when the diameter is ≥ 50 mm or an aortic dilatation expansion rate of ≥ 5 mm per year. In patients with BAV disease with additional risk factors, such as COA, Turner Syn‐ drome and a family history of aortic dissection, replacement should be considered when a diameter of ≥ 45 mm is present. Patients with symptoms of BAV disease due to AR or AS, or asymptomatic LV dysfunction all require surgery. If the ascending aorta exceeds 45 mm, the root should be replaced as well. Valve sparing aortic root replacement procedure is recom‐ mended in young patients who present with aortic root lesion with normally functioning aortic valve including the absence of calcified aortic valves, multileaflet prolapsed and an‐ nular dilatation. Future studies are mandatory, not only to predict the optimal timing for AVR when symptoms occur, but also to investigate whether prophylactic intervention of the ascending aorta at the time of AVR is necessary. Also, additional studies are required to de‐ termine the risks factors for aortic dissection and the optimal diameter at which replacement of the ascending aorta should be performed in patients with BAV disease. Future studies should also focus on sudden cardiac death in young adults with BAV disease who partici‐

both long-term survival and quality of life in patients affected by BAV disease.

in the major TAVI studies. Future research should focus on novel valve designs.

pate in athletic activity.

gets to prevent calcification, degeneration and aortic dilatation.

Nevertheless, mild-to-moderate AS is well tolerated by pregnant women and show no complications with respect to labour compared to pregnant women with severe AS who had a deterioration rate of 10% [126].

Asymptomatic severe AR is well endured by pregnant women unlike severe AS [129]. A possible explanation for this phenomenon is because of pregnancy related physiologic changes which presents with an afterload decrease and heart rate increase with a shortening of the diastole, thus reducing the level of AR.

Of note, several recommendations has to be considered in pregnant women with severe BAV pathology with symptoms including pre-pregnancy counselling, foetal echocardiography during the second trimester to investigate whether cardiac defects is present in the foetus, and close cardiac follow-up in the form of echocardiography to monitor changes in symptoms and further valve deterioration [39]. Several side effects have been reported when cardiac surgery requiring cardiopulmonary bypass is used including the potential risk of fetal distress, fetal wastage and growth retardation [130, 131]. Therefore, it should be noted that women with a high risk for complications during pregnancy should abstain from pregnancy until the valve pathology is properly surgically treated [124]. Moreover, parents should receive proper clinical counselling with respect to the genetic predisposition and the risk of congenital cardiac defect in their children [132].

Encouraging results have been observed with the balloon valvuloplasty during pregnancy including successful completion of the pregnancy [133]. However, concerns have been raised regarding symptomatic AR after balloon valvuloplasty which is also a burden for pregnant patients. Therefore, balloon valvuloplasty should be considered as a bridge to surgery in pregnant women with severe AS. When an unplanned pregnancy occurs in women with severe aortic pathology with symptoms, physical restriction with close cardiac follow-up are obli‐ gated. Furthermore, vasodilatation and volume depletion medicine should be avoided at all time. Due to the compression of the inferior vena cava by the gravid uterus, it is recommended that the delivery should be performed in the left lateral decubitus position.
