Final answer:
The majority of sexually active adolescents report using condoms, the most common form of birth control used globally, during the most recent sexual intercourse. They protect against pregnancy and STIs, with an 18 percent failure rate for pen_is condoms and 21 percent for vagina condoms with typical use.
Step-by-step explanation:
Regarding contraceptive use, the majority of sexually active adolescents report using condoms during the most recent sexual intercourse. Condoms are a barrier method of contraception that helps to prevent pregnancy by blocking sperm from entering the uterus. They are the most commonly used method of birth control globally, with pen_is condoms being more widely used, less expensive, and more readily available compared to vagina condoms. Condoms not only help in preventing pregnancy but also offer protection against sexually transmitted infections (STIs).
When comparing the typical effectiveness of various contraceptive methods, hormonal methods are generally more effective than barrier methods. However, even with typical use, pen_is condoms have an 18 percent failure rate, and vagina condoms have a 21 percent failure rate which is lower than other methods such as the fertility awareness method or spermicides used alone.
Choosing an effective method of contraception is critical, and a newly developed method with a 35 percent failure rate would not be considered highly effective compared to existing methods.