From the Research
A 5cm placental venous lake at 20 weeks gestation is generally not a cause for concern, as most venous lakes are considered normal variations in placental structure rather than pathological findings 1. These venous lakes, also called subchorionic lakes or placental lakes, are common findings during pregnancy ultrasounds and represent areas of maternal blood within the placenta. While the 5cm size is on the larger end, the presence of placental lakes does not appear to be associated with uteroplacental complications or an adverse pregnancy outcome 1.
Some key points to consider:
- Placental lakes are more prevalent with increasing placental thickness 1
- There is no significant association between placental lakes and maternal socio-demographic factors, perinatal mortality, maternal cigarette smoking, birth weight below the 5th centile, pregnancy-induced hypertension, severe pre-eclampsia, or placental abruption 1
- The diagnosis and treatment of placental lakes require close collaboration between sonographers, obstetricians, geneticists, and pathologists 2
It's essential to attend all scheduled prenatal appointments so your doctor can track any changes in the venous lake's size or characteristics. If you experience any unusual symptoms like vaginal bleeding or decreased fetal movement, contact your healthcare provider promptly, though these would likely be unrelated to the venous lake itself. Your healthcare provider will likely monitor this finding during subsequent ultrasounds, but no specific intervention is typically needed 3.