 We explain how to prevent unwanted pregnancy and sexually transmitted diseases. This is Lena and her boyfriend, Kamal. They have just fallen in love and they want to sleep with each other for the first time. Of course, they know about the risk of pregnancy, but they consider themselves way too young to have a child. Because of that, talking about contraception before their first time is important. They already know of the contraceptive pill, the coil, and condoms, but this information is too basic. How does birth control actually work and which method is the safest? These questions are answered by a gynecologist. In order for a woman to get pregnant, her body releases an egg cell from her ovaries. It moves into the womb where it waits for a sperm cell to fertilize it. If the egg cell is fertilized, the concentration of the feminine sex hormone estrogen increases in the blood. Among other things, this messenger has the task of informing the body of the pregnancy. If a woman is on the pill, the dose of estrogen raises her hormone level. The body believes that it's pregnant and stops the production of new egg cells. No egg cells, no pregnancy. But there are also contraceptives that work without hormones. They prevent a pregnancy by stopping the sperm on its way to the egg cell. Condoms, copper coils, and the diaphragm work in this way. You can check the safety of a method through the Pearl Index, which calculates the annual number of pregnancies per hundred women. The safer a method, the lower the value. Top of the list is the pill. With less than one pregnancy per year, when using a condom, the risk of getting pregnant is slightly higher. However, it is the only contraceptive that protects against sexually transmitted infections. For example, the immunodeficiency disease HIV. Now, Lena and Kamal know the score. Speaking about scoring, Kamal's friend Jonas is a real lady's man. A lot of girls like him. That's why Kamal slips him a few condoms. As always, safety first.