VP02.15: Mermaid Syndrome (sirenomelia): a Case Report of Rare Congenital Anomaly

Mermaid syndrome is a rare fatal congenital anomaly, an incidence of 0.6 in 100,000 births and approximately 350 cases have been reported in the literature. In there is an evolutionary defect in the caudal region, causing varying degree of leg fusion, producing a fetus resemble to the mermaid. Severe malformations of genitourinary, gastrointestinal and cardiovascular systems usually associated with mermaid syndrome. Uncontrolled diabetes mellitus and monozygotic twinning are the major risk factors for its occurrence. Here we present a case of mermaid syndrome in a woman with insulin dependent diabetes mellitus. A 36-year-old woman delivered a baby at 36 weeks of gestation. The birthweight of the baby was 2.34kg. On examination neonate had a flat dysmorphic facial appearance and lower limbs were fused from the thigh downwards. Baby had an ambiguous genitalia. Baby died within 20 minutes after delivery. There was no history of parental consanguinity. She was diagnosed to have an insulin dependent diabetes mellitus for last four years and had satisfactory glycemic control with basal bolus insulin regimen. She was otherwise healthy with no known history of genetic or congenital abnormality in her family. There was no history of exposure to teratogenic agents during the antenatal period. An isolated mermaid syndrome with a fusion of lower limbs is less fatal. In 92% cases of mermaid syndrome associated with other fatal anomalies. Surviving babies without fatal anomalies need a multidisciplinary approach for the management. Since, it has a strong association with diabetes mellitus; meticulous glycemic control during the period of organogenesis may reduce the incidence. The sirenomelia and associated fatal anomalies can be detected by detailed obstetric ultrasound scan, and parents can be counselled about the prognosis and they can make their own decision about their baby following counselling.