Echogenic yolk sac

An echogenic yolk sac is an indeterminate finding in first-trimester fetal ultrasound. It differs from a calcified yolk sac, in that the contents of the yolk sac are echogenic, not just the rim.

One study has suggested that this finding is associated with fetal demise, but other reports in the literature suggest that there may be no association .

Practical points 

• indeterminate abnormal yolk sac abnormality that should not be considered alone for the diagnosis of failed early pregnancy 
• follow-up ultrasonography at 7-14 days to assess the pregnancy for viability is generally appropriate