EP07.51: An early ultrasound diagnosis of sirenomelia (mermaid syndrome)

A case of sirenomelia (mermaid syndrome), a rare condition with a prevalence of 1:100,000 live births, detected at 12-weeks of gestation in a healthy woman. Sirenomelia is characterised by legs fused together in a mermaid-like appearance. Other features of sirenomelia include gastrointestinal, urogenital abnormalities and a single umbilical artery. The first trimester dating scan found the femora were close together and the lower legs were not seen. There was a cystic structure in the fetal abdomen and an absent fetal bladder. The CRL 60.7mm (12 weeks 2 days) and an NT of 1.4mm. On a fetal medicine detailed scan there was a right sided anechoic avascular cystic structure (10.4x7.4x12.7mm) in the abdomen and a single umbilical artery. The right kidney and fetal bladder were not identified. These findings were suspicious for Sirenomelia. The patient opted to have a CVS and whilst awaiting the results opted for a TOP. CVS SNP array showed a female fetal profile with no known genomic imbalance. Low and high maternal age are associated with this syndrome as well as GDM. In addition, exposure to teratogens is a risk factor. 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.