Ever since men and women understood how to have children, they've also been trying to understand how to prevent this process. The history of birth control dates back thousands of years to ancient civilizations. Some methods were quite crude and downright toxic, such as a concoction of mercury and lead that Chinese concubines drank before sex. While this did reduce fertility, it also caused major organ damage and ultimately death.
But out of the multitude of crude methods, some were actually successful. For example, condoms made from fish bladder, linen sheaths, and animal intestines showed some moderate level of effectiveness.
By comparison, today's options for contraceptives are much more effective and easy to come by. They work mainly by three modes: blocking the sperm, disabling the sperm, or by suppressing the release of the egg. Male and female condoms, for example, block the sperm from ever reaching the egg; thus, fertilization is averted. In the same way, spermicides disable the sperm's ability to swim to the egg.
While ways to block or disable sperm have been around for a while, it was only in the 1960 when the FDA approved the first oral contraceptive that works to suppress the release of the egg. Since then, millions of women have been on prescription birth control, exercising their right to choose when to have children, and how many children they want.
Still, even with these innovations, nearly 220 million women are without access to reliable birth control. And until researchers find new male contraceptives, the burden of birth control still relies heavily on women.