Which statement does NOT apply to spermicides and barrier devices as methods of contraception?

Spermicides and barrier devices, such as condoms and diaphragms, serve primarily to prevent pregnancy by creating physical or chemical barriers to fertilization. The statement that they are not effective against sexually transmitted diseases (STDs) highlights a critical aspect of barrier contraception. While these methods can inhibit sperm from reaching the egg, they do not always provide reliable protection against STDs, except for male and female condoms, which are proven to reduce the risk of many sexually transmitted infections.

The correct statement indicates that barrier methods and spermicides do offer some level of effectiveness, but this effectiveness can vary significantly, particularly when compared to other contraceptive methods, such as hormonal options. Some barrier devices can be used alongside other contraceptives to enhance their effectiveness, making them part of a broader strategy for family planning.

Understanding these nuances ensures better awareness of reproductive health options and informs individuals about their limitations and benefits. Barrier methods and spermicides are useful tools, but they are not panaceas for both pregnancy prevention and STD protection.