Placental venous lakes
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.
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Epidemiology
Placental venous lakes are a common occurrence, reported to occur in approximately 20% of pregnancies.
Pathology
They usually result from perivillous fibrin deposition with cystic change within areas of subchorionic fibrin.
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 5
Markers
- the presence of placental lakes is associated with increased maternal serum alpha-feto protein (MSAFP) levels
Radiographic features
Antenatal ultrasound
- relatively well defined hypoechoic regions within the placenta
- colour Doppler imaging may show low-velocity laminar flow within
Differential diagnosis
- placental chorangioma: shows marked internal vascularity on colour Doppler imaging
Related articles
Placental pathology
-
placenta
- placental anatomy
- placental developmental abnormalities
- placenta previa
- spectrum of abnormal placental villous adherence
- abnormalities of cord insertion
- abruptio placentae
- placental pathology
- vascular pathologies of placenta
- placental infections
- placental masses
- molar pregnancy
- twin placenta
- miscellaenous