Late Second Trimester Diagnosis of Sirenomelia

Abstract

Sirenomelia is an uncommon complex congenital anomaly associated with fusion of the lower limbs and abnormalities of the urinary and gastrointestinal tract. Most cases of sirenomelia are not diagnosed in utero due to the complexity of the anomalies coupled with anhydramnios. With a male predominance of approximately 3:1, amniocentesis or noninvasive prenatal screening is the only way to confirm the chromosomes and gender of fetuses diagnosed with sirenomelia in utero. Few cases have been reported surviving past the neonatal period and a majority die in utero.