MULTI FACTORICAL DISORDERS AND STRUCTURAL ABNORMALITIES
These are defects caused by an interplay of environmental factors and gene that is expressed usually as physical defects. The commonest physical defect are the open neural tube defects such as spinal bifida and heart defects (hole in the heart) such as ventricular septal defects. Approximately 99% of these defects may be detected through advanced ultrasound examination, testing for the fetal proteins such as alpha-fetoprotein (AFP) and acetylcholinesterase (AChE) in the amniotic fluid and maternal serum and coloured droppler imaging. Skull and spine defects which are too small or covered by skin (closed) cannot be detected by these tests. Ultrasound alone does not detect all of the anomalies. The 3D scan has a special advantage in the diagnosis of facial cleft such as cleft lip.
