Abstract
Sirenomelia is a rare congenital anomaly characterized by a single lower extremity which is associated with abnormalities in other organ systems, commonly affecting the gastrointestinal and the urogenital systems. It is sporadic with no increased risk in subsequent pregnancies. In almost all the cases of sirenomelia, a single umbilical artery (SUA) is present which arises from the abdominal aorta. Sirenomelia can be confidently diagnosed in the first trimester while the diagnosis in the second and third trimesters is rendered difficult due to the lack of amniotic fluid in the later gestation. Transvaginal ultrasound and color Doppler have a key role in making the diagnosis and 3D ultrasound helps in better demonstrating the abnormality.
Keywords
Sirenomelia - Ultrasound - First trimester diagnosis - Single umbilical artery - Severe oligohydramnios
