“… 3 However, considering the clinical situation of the patient, such as NYHA functional class IV, the need for intensive care, mechanical mitral prosthesis with a thrombus size > 0.8 cm², the surgical treatment was chosen. 4 - 6 ) Despite the established supportive care, while waiting for the previously indicated definitive surgical therapy, the patient showed clinical deterioration and died, alerting us to the potential severity of a prosthesis thrombosis picture, which requires an emergency procedure (surgical or thrombolysis), regardless of aggravating factors such as the pregnancy itself or associated infections. (Dr. Vinícius Araújo de Freitas Chagas Caldas and Dr. Daniel Valente Batista)…”