Diagnóstico prenatal de 2 casos de sirenomelia en el primer trimestre

Sirenomelia, or mermaid syndrome, is a rare malformation condition that is characterised by there being only one lower limb, absence of sacral bone, a single umbilical artery, urogenital abnormalities, and an imperforate anus, among other possible anomalies. The aetiology is unknown and the prognosis is generally poor. Prenatal diagnosis in the first trimester is uncommon, but lately, new published reports on isolated cases are appearing. We present 2 cases diagnosed in the 12 week of pregnancy in mothers with no history or risk factors. Illustrations of the ultrasound studies are presented, as well as photographs of the specimens after the interruption of the pregnancy.