Congenital anomaly is defined as developmental defect present at birth. Types of congenital anomalies: 1. Structural, 2. Functional, and 3. Metabolic. Causes of congenital anomalies: 1. Genetic factors and Environmental factors. Genetic factors: chromosomal anomalies: 1. Numerical: (a) aneuploidy and (b) polyploidy. 2. Structural: (a) translocation, (b) deletion, (c) duplication, (d) inversion, and (e) isochromosomes. Environmental factors: 1. Drugs, 2. Chemicals, 3. Infectious agents, 4. Radiation, and 5. Mechanical factors.