[Sirenomelia: a case report].

Sirenomelia is a rare congenital anomaly characterized by fusion of the lower extremities and multiple visceral abnormalities. It usually has a lethal prognosis due to the severity of the associated abnormalities. We present the case of a 26-year-old female patient, in her second pregnancy without associated comorbidities, who was admitted to the Emergency department due to a 26-week pregnancy and anhydramnios. She subsequently underwent an ultrasound in the Maternal Fetal Medicine service, who performed the Sirenomelia diagnosis. It was decided to terminate the pregnancy due to the poor prognosis.