Case report

This is a second trimester fetus (28 weeks of gestational age). Our ultrasound examination revealed the following findings:

• Double aortic arch : the aortic arch bifurcates directly at the level of trachea to have one arch to the right and one to the left ( lambda sign ). The esophagus and trachea are entrapped between the right and left arches. Left arch is generally narrower or hypoplastic.

• Generally, the descending aorta has a left side course and connects with left arch.

• Color Doppler images show lambda bifurcation in front of trachea and the course of vessels.