Contraception

• Pregnancy starts when the woman's FSH stimulates an egg in one of the ovaries to develop, and then after about three weeks the hormone LH triggers the release of an egg, which passes along the adjacent fallopian tube and could combine with a sperm cell to form a fertilized egg.
• If a fertilized egg does combine with a sperm cell, it would continue along the fallopian tube to the uterus, where it would implant into the wall and slowly develop into a fetus.
• The cervix is the entrance to the uterus.
• Contraception has to interrupt the process of pregnancy by either preventing the release of an egg, preventing fertilization, or preventing the implantation of a fertilized egg.
• One way to categorize all the different methods of contraception is to split them between those that use hormones and those that don't.
• Hormonal methods of contraception rely on releasing estrogen, progesterone, or some combination of the two.
• Estrogen steadily every day inhibits the production of FSH, which normally stimulates egg development, meaning no egg will develop.
• Progesterone stimulates the production of thick mucus in the cervix, which prevents the sperm from ever reaching the egg.
• The combined contraceptive pill, which contains a combination of both estrogen and progesterone, is over 99% effective at preventing pregnancy as long as the pills are taken properly, but it can sometimes have side effects such as headaches or nausea.
• The progesterone only pill is as effective as the combined pill but tends to have fewer side effects.
• Progesterone is slowly released for up to three years from the progesterone-only pill.
• The intrauterine device (IUD) is placed inside the uterus and releases progesterone which stimulates the production of a thick mucus in the cervix.
• The copper IUD, also known as the copper coil, is not a hormonal contraceptive and does not involve any hormones, it just prevents sperm from surviving in the uterus by killing them.
• Both the plastic and copper IUD can last over three years.
• Non-hormonal methods of contraception work by preventing the sperm from meeting the egg, for example, condoms are worn over the penis which traps any sperm.
• Female condoms are worn inside the vagina and do the same thing.
• Condoms are the only form of contraception that also protect against sexually transmitted diseases (STDs).
• The diaphragm is a shallow plastic cup that fits over the cervix to block sperm from entering the uterus, but it's not very reliable and must be used with spermicide, a substance that kills sperm.
• Spermicides can be used alone as a form of contraception but they only work around seven out of ten times, making them not very reliable.
• Sterilization in women involves cutting or tying the fallopian tubes which connect the ovaries to the uterus, preventing the eggs from passing from the ovaries into the uterus.
• Men can also undergo sterilization by having their sperm ducts cut and tied.
• Natural methods of contraception include only having sex at certain times of the month or stopping sex just before ejaculation, but these are both very unreliable and not recommended.
• The only way to be 100% sure of avoiding pregnancy is by abstaining from sex altogether.
• Other methods of releasing hormones include the contraceptive patch, which is a small sticker that you place on the upper arm which slowly releases estrogen and progesterone, each patch lasting one week, the contraceptive injection, which is an injection of progesterone into the upper arm with each dose lasting two to three months, and the contraceptive implant, which involves a small device being placed under the skin of the arm.