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Amniotic membrane

Case contributed by Matt A. Morgan
Diagnosis certain

Presentation

Normal first trimester fetal ultrasound corresponding to 8 weeks 5 days

Patient Data

Age: Adult
Gender: Female
Annotated image

The blue arrows point to a curvilinear echogenic membrane within the gravid uterus. This is the amnion / amniotic membrane. The chorionic membrane is outside the amniotic membrane, out at the edge of the anechoic gestational sac and not visible.

Note how the yolk sac is always outside the amniotic sac.

Case Discussion

Single ultrasound image of a first trimester fetus to illustrate the amniotic membrane and its relationship to the fetus, yolk sac, and chorionic sac.

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