First Trimester Diagnosis of Sirenomelia: A Case Report

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.

First‐trimester sonographic diagnosis of sirenomelia: A multicenter series of 12 cases and review of the literature

“…The literature review identified a total of 23 cases from 21 reports (Table ) . Six additional cases diagnosed in the first trimester but described as part of three large series of sirenomelia were not included in the analysis .…”

“…Additional major malformations were noted in five cases (22%), including one case of acardius . Four others had an abdominal wall defect, including three with a liver containing omphalocele and one with a large anterior abdominal cyst . Color flow imaging was used in 17 cases (74%), mainly to detect SUA (n = 16, 69%) and to document the aberrant abdominal vessel (n = 9, 39%).…”