Abstract
Sirenomelia or the mermaid syndrome is a rare and lethal congenital anomaly. It is
characterized by fusion of lower extremities. It is associated with bilateral renal
agenesis, anomalies of rectum, sacrum, cardiovascular system and abdominal wall. Pathognomic
finding is a single umbilical artery, the ‘persistent vitelline artery’ which distinguishes
sirenomelia from caudal regression syndrome. Sirenomelia has strong association with
maternal diabetes mellitus. We report a case of sirenomelia diagnosed in first trimester.
Early diagnosis was possible as protocol-based anatomic evaluation was performed.
Diagnosis of sirenomelia is easier in first trimester as severe oligohydramnios in
later gestation hampers the fetal evaluation.
Keywords
First trimester fetal anomalies - Early diagnosis - Sirenomelia
