COLOR DOPPLER IMAGING OF THE

ABNORMAL FIRST TRIMESTER

NORMAL GESTATION

• During first 12-13 weeks uteroplacental and fetoplacental circulations are not in direct contact with each other.
• Sonographically there is no active blood flow in the intervillous space.

ABNORMAL GESTATION

• Blood flow in the intervillous space.
• Reduced trophoblastic invasion of the decidual arteries have been identified in early miscarriages, with the vessels maintaining their contractility functions, however the resistance to flow remains high (1).
• Morphopathologic studies have demonstrated reduced trophoblastic invasion of the spiral arteries, while sonographic studies have shown an increased resistance to blood flow in the spiral arteries and the abnormal presence of arterial blood flow in the intervillous space (1,2). It is thought that the high pressure blood flow may cause significant pressure on the immature placenta resulting in disengagement of the early villi and subsequent miscarriage (3).

REFERENCES

1. Hustin J, Jauniaux E, Schaaps JP. Histological study of the materno-embryonic interface in spontaneous abortion. Placenta 1990;11:477-486.
2. Jauniaux E, Jurkovic D, Campbell S. In-vivo investigations of the anatomy and physiology of early human placental circulation. Ultrasound Obstet Gynecol 1991;1:435-445.
3. Jaffe R, Dorgan A, Abramowicz JS. Color Doppler Imaging of the Uteroplacental Circulation in the First Trimester: Value in predicting pregnancy failure or complication. AJR 1995;164:1255-1258.