Antenatal diagnosis of absence of septum pellucidum

The absence of septum pellucidum (ASP) is a rare disease, which affects the structure of the brain. It is either isolated or associated with various congenital brain malformations. The diagnosis of ASP can be performed by second‐trimester ultrasound. When the ASP is isolated, prenatal counseling is optimistic regarding neurological outcome, but there is a 20% risk of septo‐optic dysplasia in the neonate.