EP17.19: Prenatal diagnosis of sirenomelia: different manifestation of four cases – the same fetal anomaly

Abstract

Sirenomelia or mermaid syndrome is a rare birth defect with an incidence of about 1 in 60 000 births. There is a higher incidence in males than females, with a ratio of 2,7 to 1. Similar to mythological siren the syndrome is characterised by fusion of lower extremities or single lower limb. Classification of sirenomelia is based on number of feet. Despite of limbs malformations there are several internal abnormalities like: sacral agenesis, anorectal atresia, renal agenesis, cystic renal dysplasia, agenesis of internal genital organs and ambiguous external genitalia. Other findings that occur commonly include cardiovascular disorders, abdominal wall defects, severe scoliosis and other skeletal deformities. None of etiological theories is proved like a vascular steal, caudal defect, genetic failures or teratogenic influence of retinoid acid or irradiation. Some researches proved that trypan blue or ochratoxin. A animal exposition may cause sirenomelia. No proofs of chromosomal aberrations in humans were found. Sirenomelia is considered to be a lethal defect which often indicates to terminate the pregnancy. Therefore, this serious diagnosis must be restrictly confirmed by any possible methods. First or early second trimester ultrasound anatomy survey of the fetus is proposed as preferable. We present 4 cases of sirenomelia who were diagnosed within an interval of 2 months in our department. We discuss difficulties of sonography diagnosis and we are looking for epidemiologic links between these cases. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.