Sirenomelia: Mermaid Syndrome

Sirenomelia: Mermaid Syndrome

Sirenomelia, also known as Mermaid Syndrome, is an extremely rare and often fatal congenital disorder. This condition is characterized by the fusion of a baby’s legs, forming a structure that resembles a mermaid’s tail. The name Sirenomelia comes from this unique appearance.

What is Sirenomelia?

Sirenomelia is an exceptionally rare congenital anomaly that occurs in approximately one in 100,000 births. This condition is defined by the fusion of the legs at birth. In cases of Sirenomelia, the tissue and bone structure between the legs do not fully develop, resulting in a fish tail-like appearance.


The exact causes of Sirenomelia are not fully understood, but it is believed that a combination of genetic and environmental factors contribute to this condition. Factors that may increase the risk of Sirenomelia include inadequate blood flow from the placenta, maternal diabetes, or exposure to certain medications and chemicals.


The most noticeable symptom of Sirenomelia is the fused legs. However, this condition is usually accompanied by the following symptoms:

  • Kidney anomalies: It is common for babies to have one or both kidneys missing.
  • Genital and urinary system anomalies: Underdevelopment of the genital organs and urinary system is frequently observed.
  • Digestive system problems: The anus and rectum may not develop properly.
  • Spine and rib deformities: Various abnormalities in the spine and rib structure can occur.
  • Heart and lung issues: The heart and lungs may also be affected in these cases.


Sirenomelia is usually diagnosed through ultrasound during the second trimester of pregnancy. During the ultrasound, the fused legs and abnormal development of other organs can be seen. In such cases, doctors may conduct additional tests to make a more detailed diagnosis.

Treatment and Management

Treatment for Sirenomelia is extremely challenging, and the chances of survival for the baby are generally low. However, in some cases, babies can survive with various surgical interventions after birth. These surgeries may include separating the legs, kidney transplantation, and correcting digestive system anomalies.

Living with Sirenomelia

Most babies born with Sirenomelia pass away shortly after birth. However, in some rare cases, children manage to survive thanks to surgical interventions and medical care. These children face significant physical disabilities and health issues.

Doctors of the Relevant Department:

Speck. Dr. Muharrem ÇİÇEK

Spec. Dr. Farida AKBAROVA

Speck Dr. Feyzullah YESEVİ

Speck Dr. Muhammed Yusuf MİLA

Speck Dr. Ayşegül ÖRENCİK