Placental lake

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. They can, however, be abnormal if very diffuse or if seen very early in pregnancy.

Epidemiology

Placental lakes are a common occurrence, reported to occur in approximately 20% of pregnancies.

Associations

Their presence tends to be associated with:

• increased placental thickness
• placenta accreta spectrum and abnormal placental villous adherence
• placental insufficiency, especially if seen early in pregnancy

Pathology

They usually result from perivillous fibrin deposition with cystic change within areas of subchorionic fibrin.

Markers

• the presence of placental lakes is associated with increased maternal serum alpha-fetoprotein (MSAFP) levels

Radiographic features

Antenatal ultrasound

• relatively well defined hypoechoic regions within the placenta
• color Doppler imaging may show low-velocity intraplacental laminar flow

Differential diagnosis

• placental chorioangioma: shows marked internal vascularity on color Doppler imaging

Siehe auch:

• Plazentainsuffizienz
• abnormal placental villous adherence
• placenta accreta spectrum
• increased maternal serum alphe-feto protein (MSAFP)

und weiter:

• altered alpha fetoprotein levels
• Entwicklungsanomalien der Plazenta
• placental cyst
• Chorioangiom der Plazenta
• placental septal cyst
• venöse Seen oder Lakunen