Fetal brain herniating through mouth

According to A2Z group on Facebook. Encephalocele(fetal brain) herniating through mouth

Encephaloceles are rare birth defects associated with skull defects characterized by partial lacking of bone fusion leaving a gap through which a portion of the brain sticks out (protrudes). In some cases, cerebrospinal fluid or the membranes that cover the brain (meninges) may also protrude through this gap. 

In some cases, cerebrospinal fluid or the membranes that cover the brain (meninges) may also protrude through this gap. The portion of the brain that sticks outside the skull is usually covered by skin or a thin membrane so that the defect resembles a small sac. Protruding tissue may be located on any part of the head, but most often affects the back of the skull (occipital area). Most encephaloceles are large and significant birth defects that are diagnosed before birth. However, in extremely rare cases, some encephaloceles may be small and go unnoticed. 

The exact cause of encephaloceles is unknown, but most likely the disorder results from the combination of several factors (multifactorial).
Images courtsey of A2Z ultrasound