A counseling dilemma involving anencephaly, acrania and amniotic bands.

A suggested fetal anencephaly on routine office ultrasound examination resulted in a diagnosis of fetal acrania when targeted ultrasonography was performed by a consultant. Following pregnancy termination, examination of the abortus revealed partial cranial destruction secondary to an amniotic band. It is often difficult to distinguish between anencephaly, acrania, and amniotic band sequence prenatally, but postnatal differentiation is imperative for accurate risk assessment in genetic counseling.