A 16-year-old girl can also have an intrauterine device (IUD) placed, but the development of her reproductive organs is not particularly mature at the age of 16, and intrauterine placement of the IUD is generally not recommended. If you have a boyfriend or are married and do not have childbearing requirements, you can still place an IUD to avoid accidental injuries that could cause more damage. 16-year-old girls who are not married are advised not to have sex because the reproductive organs are immature and can easily cause damage and cervical lesions. So girls should be self-respecting and not cause damage to themselves because of momentary pain.