Progressive calcification of bioprosthetic mitral valve observed during pregnancy resulting from in vitro fertilization: a case report

Abstract

Background: Women with pre-existing cardiac conditions who undergo assisted reproductive technologies (ART) are believed to be at a heightened risk of cardiovascular events during both the treatment and pregnancy phases. An unresolved question within this context pertains to whether the ART procedure itself constitutes a risk factor for individuals with bioprosthetic heart valves (BHV). Additionally, there is ongoing controversy regarding whether pregnancies expedite the process of structural valve degeneration (SVD) in BHV. The purpose of this study is to present the developmental process of BHV calcification, which is considered the primary cause of SVD, during a pregnancy resulting from in vitro fertilization and embryo transfer (IVF-ET), an ART modality, and to elucidate the underlying mechanisms.

Case presentation: At 7 + 3 weeks of gestation in a twin pregnancy resulting from IVF-ET, a 27-year-old woman with a bioprosthetic mitral valve manifesting severe mitral stenosis and moderate pulmonary arterial hypertension, was suspected of SVD. Despite undergoing fetal reduction, she experienced progressive calcification of the bioprosthetic valve, increasing pulmonary arterial pressure and ultimately deteriorated into heart failure. An elective cesarean section and redo valve replacement was subsequently administered to improve her cardiovascular condition. As a result, a healthy young boy was delivered and the dysfunctional BHV was replaced with a mechanical valve. She did not report any discomfort during the 3-month follow-up.

Conclusion: The progressive calcification of the BHV was observed during IVF pregnancy, indicating a potential connection between fertility therapy, pregnancy and calcification of BHV. Pregnant women with pre-implanted BHV should be treated with caution, as any medical interventions during ART and pregnancy can have a significant impact on both maternal and fetal outcomes. Thus, involving a multidisciplinary team in decision-making early on, starting from the treatment of the original heart disease, throughout the entire process of ART and pregnancy, is crucial.

Keywords: Bioprosthetic heart valve; Calcification; In Vitro Fertilization; Pregnancy; Structural valve degeneration.

Fig. 1

Transthoracic echocardiography and cardiac computed tomography examination results. The parasternal long-axis views of two-dimensional echocardiography throughout the pregnancy procedure illustrated the progressive calcification of her bioprosthetic mitral valve (arrow) (A–E). This progression can be inferred from the gradual thickening of the leaflets, narrowing of the orifice diameters (decreasing from 0.871 cm to 0.547 cm), and the enhancement of echoes observed during the examinations conducted on 10-17-2022 (A), 12-19-2022 (B), 2-23-2023 (C), 3-20-2023 (D), and 4-3-2023 (E). Cardiac computed tomography revealed the enlarged pulmonary trunk with a diameter of 44 mm (reference level : < 29 mm), and a higher pulmonary trunk to ascending aorta ratio of 1.632 (reference level: <1.0), both indicating the pulmonary arterial hypertension (F)

Fig. 2

Photo of the removed mitral valve. The removed implanted bioprosthetic mitral valve showed significant calcification