What is venous lake in placenta?

Placental (venous) lakes refer to a phenomenon of formation of hypoechoic cystic spaces centrally within the placenta. Finding placental lakes during a second trimester ultrasound scan is not associated with any uteroplacental complication or with an adverse pregnancy outcome.

What causes venous lakes in placenta?

The causes of venous lakes are unknown, but it may be associated with a placenta that is rooted deeper in the uterus, which is called accrete (see my article called Let’s Talk Placenta). It may also be associated with women who have had uterine surgery.

What is the significance of placental lakes?

Conclusion: Large placental lakes were correlated with the fetal status of small for gestational age. Therefore, if a large placental lake is identified in the 2nd trimester of pregnancy, appropriate surveillance should be considered for the remainder of the pregnancy.

Where are the placental lakes in an ultrasound?

The blood-filled placental lakes appear nearly black (white arrows) on ultrasound because they do not reflect soundwaves back to the ultrasound machine. Placental lakes can be seen within the placenta or on the fetal surface of the placenta bulging into the amniotic cavity.

What makes a placenta a placental venous lake?

Placental lakes or placental venous lakes are spaces within the placenta filled with maternal blood. A placental lake could contain small dilated veins with maternal blood flowing through them (1). How Common Are Placental Lakes?

What does an ultrasound image of the placenta show?

These ultrasound images suggest a typical appearance of a large venous lake in the placenta. Color Doppler image showed no major flow pattern within this placental lake. The fine, echogenic strands within the lesion appear to be nothing more than artefacts produced by slow flowing blood within the lesion.

How to tell a placental lake from a thrombus?

Slow swirling blood flow (larger arrow) may be seen within the spaces, and the shape of the spaces tends to change with uterine contractions. These features may help to distinguish a placental lakes from a thrombus.