The uterus of a 16-year-old girl is well developed, and the female hormones are beginning to be secreted, and the female sex characteristics are slowly coming out. 16-year-old girls can also get pregnant if they have sex, so the uterus of a 16-year-old girl is primed to function. 16-year-old girls’ uterus is close to the size of the uterus of women of childbearing age, generally about 7cm in length, 4cm in width, 2-3cm in thickness, and about 50g in weight. Weight about 50g, is slightly flat front and back inverted pear-shaped. So 16-year-old girls are recommended to reduce as much as possible, avoid the occurrence of sexual life, and if sex occurs must pay attention to contraception.