Abnormal sonographic appearances of the yolk sac: which can be associated with adverse perinatal outcome?
The yolk sac performs important functions for embryonic development and the remnant seen on ultrasonography is considered to be a potential predictor of fetal outcome. There has been one previous report describing the association of a hyperechogenic yolk sac with aneuploidy (Szabó et al. 1996). If this association can be confirmed, then the presence of an echogenic yolk sac on ultrasound could prove to be an additional first trimester marker.