Threatened Abortion - Part 4
Confirming Embryonic Demise with Absence of Heart Beat

what size should embryo without heart beat be to confirm demise

• You can reliably confirm embryonic demise if the embryo is > 7 mm without a heart beat
• Prior to the 2014 Consensus Conference, this number was > 5 mm

criteria to IDENTIFY a "globular" embryo without a heart beat

• If you are using the embryo size to determine demise, it is important to be sure that you are, in fact, actually measuring the embryo! 
• This may sound fundamentally simple, however an embryo without a heart beat is just a tiny "glob" of echoes. We refer to this as a globular embryo. 
• There are 2 findings that can help you to make sure that you are measuring the correct glob of echoes
  • It should lie in immediate contiguity with the yolk sac
    
  • It is completely surrounded by amnion

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Pitfalls

• It is important to remember that the embryonic heart is actually externalized. 
• You can thus take an image of the embryo without including the heart an erroneously concluding that there is no heart beat. 

• How to avoid this pitfall
  • Be aware. Just knowing this will put you on heightened alert
  • The heart lies adjacent to the yolk sac. If you see an image without the yolk sac and no heart beat, you may be missing the heart
  • Use cine clips. We've emphasized over and over, how helpful these are in all of ultrasound

terminology

followup RECOMMENDATIONS

• What do you do if you see and embryo that is < 7 mm without a heart beat?
  • Recommend a followup sonogram in 7-14 days