Contraception

Women can get pregnant around the time a mature egg cell has left their ovary. The moment the egg cell leaves the ovary is called ovulation. The egg cell moves along the fallopian tube and into the womb. If sperm cells manage to get through the cervix and womb, and into the fallopian tube, the egg cell may become fertilized. If a sperm cell meets the egg cell, they join together. Women become pregnant if the fertilized egg cell becomes embedded (implanted) in the lining of the womb.

Girls can become pregnant as soon as they start ovulating – in other words, when they start getting periods. Boys can already have fertile sperm cells as soon as they start ejaculating.

Different contraceptives prevent fertilization or implantation in different ways: Some, such as condoms or diaphragms, prevent sperm cells from getting into the womb through the cervix. These are collectively known as "barrier methods." The coil prevents fertilized egg cells from becoming embedded in the womb. Most hormonal contraceptives influence the monthly cycle and prevent ovulation.

Many of the various hormonal contraceptives contain a combination of hormones that prevent ovulation, thereby preventing egg cells from being fertilized. All hormonal contraceptives have to be prescribed by a doctor. The most commonly used hormonal contraceptives are:

• Birth control pills ("the pill"): These pills contain estrogen and progestin, and are taken on 21 or 22 days per cycle. The woman then has a period in the week when she doesn't take the pill. Some women use a "mini pill" instead, for example because they don't tolerate the combined pill well. Mini pills only contain progestin, not estrogen.
• The contraceptive skin patch: Contraceptive skin patches are placed on the body, where they release a combination of estrogen and progestin. The patch is changed once a week in the first three weeks of the menstrual cycle. No patch is worn during the fourth week.
• Vaginal ring: Vaginal rings also contain a combination of hormones that enter the bloodstream through the wall of the vagina. They are inserted deep into the vagina and taken out again after 21 days, using a finger. The woman then has a period in the week that follows. Women usually can't feel the vaginal ring inside them.
• Hormone-releasing contraceptive coils (IUDs or IUSs): Hormone-releasing coils contain a hormone called levonorgestrel. They are inserted into the womb by a doctor or nurse. The hormone is continuously released by the coil and absorbed by the lining of the womb. This prevents the implantation of any fertilized eggs. The coil has a contraceptive effect as soon as it is in place, and can stay in the womb for up to five years.

Other, less common, hormonal contraceptives include the three-month injection and the hormonal birth control implant.  In both cases, you can't simply stop using them. The three-month injection contains a high dose of hormones and often causes side effects. These two forms of contraception are usually only recommended for women who cannot tolerate other contraceptives or can't use them regularly.

When used properly, hormonal contraceptives are very reliable. They can also relieve period pain and reduce menstrual bleeding.

The disadvantages of hormones include possible side effects such as sore breasts, headaches and nausea. There is also a risk of blood clots developing (thrombosis). According to research, hormonal contraceptives are not likely to lead to weight gain.

Non-hormonal contraceptives have fewer or no side effects, but are considered to be less reliable than hormonal contraceptives. In many cases, though, the reliability of a contraceptive will mainly depend on whether it is used properly. Commonly used non-hormonal contraceptives include:

• Condoms for men: Condoms not only prevent unwanted pregnancies – they also prevent the spread of sexually transmitted infections or diseases such as HPV, HIV, hepatitis C, gonorrhea and syphilis. They offer reliable protection if used properly. The most common mistakes include using the wrong size, damaging the condom when taking it out of the packet, and pulling it on rather than rolling it down the penis. Condoms shouldn't be used together with greasy or oily substances such as lubricants. Doing so could weaken and damage them.
• Female condoms: These "internal" condoms are covered with a lubricant before use and placed inside the vagina. When used properly, they are as reliable as normal condoms are. A lot of women find it difficult to use them.
• Copper coils or the copper "chain": These contraceptives are inserted into the womb by a doctor or nurse. Copper makes it harder for the egg to be fertilized and become embedded in the lining of the womb: It changes the mucus in the cervix and womb, and also reduces the mobility of the sperm. Both the coil and the "chain" (a frameless copper IUD) are considered to be reliable forms of contraception, and can remain in the womb for about five years. The possible side effects include heavier periods and pelvic infections.
• Diaphragms: These soft silicone cups with a flexible outer ring are inserted into the vagina to completely cover the cervix (the opening of the womb). A gel containing a sperm-killing agent (a spermicide) is applied to the diaphragm beforehand. The diaphragm is inserted into the vagina before having sex, and must be left in place for at least six hours afterwards. Like other forms of contraception, diaphragms are only reliable if they are used properly. The gynecologist will determine the correct size of diaphragm.
• Chemical contraceptives like creams, gels or suppositories are put inside the vagina before having sex. The woman's body heat makes them runnier, and a thick, sticky barrier forms in front of the opening of the womb, stopping sperm cells from entering. A lot of chemical contraceptives also contain sperm-killing agents (spermicides). Because chemical contraceptives are quite unreliable, they should only be used together with other forms of contraception.
• Natural birth control methods: These methods are used to determine when a woman is fertile based on her body temperature in the morning, as well as on her vaginal discharge. They aren't very reliable, and require a lot of effort and discipline. Other forms of contraception, such as condoms, must be used on the days when she is fertile.

You can get more information about the different kinds of contraceptives from your doctor or women’s health center.