Sirenomelia, the Mermaid syndrome: case report and a brief review of literature.

Sirenomelia, the Mermaid Syndrome is a rare and lethal congenital anomaly with an incidence of one in 60,000 to 70,000 pregnancies. Sirenomelia is characterized by complete fusion of the lower limbs, commonly associated with renal agenesis, absent external genitalia and other gastrointestinal defects. Another pathognomonic finding is the presence of single umbilical, persistent vitelline artery which is the chief distinguishing anatomic finding from Caudal Regression Syndrome. We report a case of termination of pregnancy done on the basis of ultrasound diagnosis of bilateral renal agenesis with no liquor volume. The foetus was identified to have characteristic features of Sirenomelia at the time of termination.