[The embryonal yolk sac in disordered early pregnancy]

Area of Science:

• Obstetrics and Gynecology
• Medical Imaging
• Embryology

Context:

• Vaginal sonography is a key tool for assessing early pregnancy.
• Evaluating the yolk sac and chorionic cavity provides insights into embryonic development.
• Distinguishing between normal and abnormal early pregnancies is crucial for patient management.

Purpose:

• To determine the diagnostic value of yolk sac detection and size in early pregnancy assessment.
• To correlate yolk sac characteristics with pregnancy outcomes (normal vs. spontaneous abortion).
• To identify sonographic markers indicative of early pregnancy developmental disturbances.

Summary:

• A prospective study evaluated 377 singleton pregnancies using vaginal sonography.
• Yolk sac detection rates were significantly lower in non-viable pregnancies (34.5%) compared to normal (91.9%) or viable but aborted (100%) pregnancies.
• Yolk sac diameters >6 mm or >7 mm were strongly associated with pathological pregnancy courses, unlike normal development.

Impact:

• Establishes specific sonographic criteria for identifying early pregnancy failure.
• A non-visible yolk sac (5-10 weeks) or a yolk sac diameter >6 mm can serve as early indicators of developmental disturbance.
• Improves the accuracy of predicting pregnancy outcomes through early ultrasound assessment.