Currently, ultrasound is a well-known clinical modality for pregnancy management and has a prominent role in clinical decision-making. Accordingly, developing guidelines to outline the minimum performance standards of using ultrasound is necessary for different areas of obstetric ultrasound. The fetal brain is one of the most important assessments in anomaly scan. For a basic brain assessment, 3 axial planes are routinely defined. According to most guidelines, the fetal skull’s integrity, shape, and bone density should be assessed while measuring the head size. In this paper, we present 2 cases of skull bony defect with normal routine 3 axial planes. For better detection of CNS anomalies, it is necessary to add other views such as sagittal view to three routine planes. It leads to early detection of anomalies especially in first and early second trimester. Consequently, it helps in deciding for termination, planning interventions and further management.