Placental Lakes and Their Clinical Significance

Diagnostic Features and Differential Diagnosis

• The American College of Obstetricians and Gynecologists recommends distinguishing placental lakes from vascular lacunae associated with placenta accreta spectrum (PAS), which represent a different and dangerous pathology, characterized by multiple vascular lacunae with turbulent lacunar blood flow on Doppler 1, 2
• The presence of massively dilated uterine vessels at the uteroplacental interface, loss of the retroplacental clear zone, thinned myometrium (<1mm), and placenta previa are indicative of PAS-associated lacunae 1, 2, 4, 5, 6
• The American College of Obstetricians and Gynecologists suggests that PAS-associated lacunae occur with loss of the retroplacental clear zone, thinned myometrium (<1mm), and placenta previa 1, 2, 3

Diagnostic Approach and Management

• When placental lakes are identified, the sonographer should assess for PAS features if anterior placenta or risk factors present, and evaluate placental thickness and calcifications, as increased thickness and grade 3 calcifications before 35 weeks suggest placental dysfunction 1, 3
• The American College of Obstetricians and Gynecologists recommends referral to a level III/IV maternal care facility with multidisciplinary expertise for delivery planning when lakes are suspicious for PAS 1