A girl’s height before menarche varies from person to person, usually around 150cm, and is affected by a number of factors such as family genetics, diet, and nutritional status. Menarche refers to the time of a woman’s first menstrual period, and every normal woman has to go through this stage. The first menstrual period usually occurs around the age of 12, and the most important clinical manifestation is vaginal bleeding. A girl’s height at menarche generally fluctuates around 150cm. If a girl’s height is too short at the time of menarche, she may be suffering from malnutrition, hereditary factors in her family, or some pathologic causes, such as dwarfism. Parents are advised to seek medical advice if they find that a girl’s height is abnormal, so as to find out the cause of the abnormality and to seek medical advice.