The natural history of disease refers to the course a disease takes in an individual from its initial exposure to a causative agent or risk factor until its final outcome, such as recovery, disability, or death, in the absence of intervention. It is commonly divided into two major phases: the pre-pathogenesis phase and the pathogenesis phase. Understanding this course helps in planning appropriate levels of prevention, particularly in maternal and child health care. The pre-pathogenesis phase occurs before the disease develops. During this stage, the interaction between the host, agent, and environment creates conditions that may lead to disease. Primary prevention is mainly directed at this stage. Its purpose is to prevent the occurrence of disease by reducing risk factors and promoting health. Health promotion measures include adequate maternal nutrition, personal hygiene, physical activity, health education, breastfeeding promotion, immunization, safe drinking water, sanitation, and healthy housing. Specific protection includes vaccination of children and pregnant women, use of iron and folic acid supplements during pregnancy, tetanus and diphtheria immunization, safe sex practices, and protection against infectious diseases. The pathogenesis phase begins when the disease-causing