Prenatal Diagnosis of Sirenomelia: Cluster of Three Cases

Abstract

Sirenomelia is an extremely rare anomaly characterised by varying degrees of fusion of lower limbs. Anomalies involving uro-genital tract, colo-rectal atresia and vertebral defects are often associated. Prognosis largely depends upon concomitant visceral malformations as well as the degree of fusion defect. Classical sirenomelia is incompatible with life although there are few report of survivors. Prenatal diagnosis, though possible, is difficult to make due to associated anhydramnios and anomalies. Ultrasound is the main diagnostic modality with fetal MRI playing a complementary role. We describe three cases of fetal sirenomelia that presented within a span of 1 year and propose possible vascular insult as the cause.