Pregnancy occurs when a man and a woman have unprotected vaginal sex, allowing sperm to travel into the uterus and fertilise one of the woman’s ova (eggs). Though pregnancy is far less likely to occur at certain times of the month, sperm can live inside the womb for up to 7 days, meaning that having sex without using contraception can very often lead to pregnancy.
Contraception is a word that refers to any method used to prevent fertilisation (and therefore pregnancy) from occurring.
What types of contraception are there?
There are various types of contraception, including non-hormonal, hormonal and barrier methods. It is important to bear in mind that each method relies on correct usage and will vary in effectiveness, and that the majority of contraceptives do not provide any protection against sexually transmitted infections (STIs). If you want to protect yourself against STIs you will need to use condoms (see below).
Barrier methods of contraception (male and female)
A barrier method of contraception involves the use of a physical block that prevents sperm from reaching and fertilising an ovum. The most commonly used barrier method is the male condom (a flexible sheath worn on the penis) however there are also barrier methods that women can use, including:
- female condoms
Caps and diaphragms are flexible pieces of rounded latex or silicone, which are inserted into the vagina before sex and block the entrance to the uterus. Both have to be used with spermicide and left in for 6 hours after sex to provide maximum protection. Female condoms are similar to male condoms, and are inserted into the vagina before sex then removed and thrown away immediately afterwards.
If used correctly, all these barrier methods offer at least 92% protection against pregnancy. However, only male and female condoms can effectively protect against STIs, as diaphragms and caps do not provide complete protective coverage.
Hormonal contraception methods (female)
Along with condoms, hormonal methods of contraception are the most commonly used. Hormonal contraception can only be used by women, and typically does three things:
- prevents ovulation (the release of an egg)
- thickens cervical mucus (to block the passage of sperm into the uterus)
- thins the uterus lining (to prevent the implantation of a fertilised egg)
Combined contraceptive pill (‘the Pill’)
The most popular form of hormonal contraception is the combined contraceptive pill (well-known brands include Microgynon 30, Cilest and Yasmin), which contains the female hormones oestrogen and progesterone. There are many combined pills available, each of which will contain slightly different variations of the hormones. The combined pill must be taken at roughly the same time every day to provide effective protection against pregnancy (although most types include a week’s break in which you have a monthly bleed, similar to your normal period). Low dose versions of the combined pill (which contain less oestrogen) are also available, and usually reduce the side effects associated with the normal pill. If you think you are in danger of missing pills, you might want to consider alternative contraceptive methods.
We can safely prescribe you the combined pill and the low dose combined pill. Click here to visit our online contraception clinic, or consult our article What is the best contraceptive pill for me? for more information.
Progesterone-only pill (POP, or mini pill)
The progesterone-only pill (or mini pill) is similar to the combined pill, but contains only progesterone (Cerazette is a well-known brand). All POPs work by thickening your cervical mucus to block the entrance of sperm to the womb, but some also block ovulation. All POPs must be taken every day, with no break, and most must be taken at the same time each day, within a window of 3 hours. POPs are often prescribed to women for whom it is unsafe to take oestrogen. However, if - as with the combined pill - you think you may be at risk of forgetting to take your mini pill, it is advised that you consider alternative methods.
Contraceptive patch and vaginal ring
Two forms of contraception that are similar to the contraceptive pill are the patch (Evra) and the vaginal ring (NuvaRing). The patch is a small sticky pad that attaches to your skin and releases oestrogen and progesterone into your bloodstream. You will wear the patch for a week before putting on a new one. After three weeks you will have a break, during which time you will have a monthly bleed, similar to your normal period.
The vaginal ring is a flexible plastic ring that is inserted into the vagina and remains there for 3 weeks. The vaginal ring, like the patch and pill, contains oestrogen and progesterone, which are released into the vaginal tissue and enter the bloodstream, preventing pregnancy.
We can safely prescribe you the contraceptive patch and vaginal ring through our online clinic. Click here to learn more.
IUS (Intrauterine system)
One method of hormonal contraception that has proved extremely effective in preventing pregnancy is the intrauterine system, or IUS. It is a small T-shaped device that is inserted into the uterus by a trained medical professional. The IUS works similarly to the intrauterine device, or IUD (see below), but differs in that instead of releasing copper it releases a form of progesterone, which thickens cervical mucus and thins the womb lining. The IUS lasts for 5 years (although you can have it taken out at any time) and is more than 99% effective in preventing pregnancy. Downsides include that it can be painful to insert, and can in some cases stop your periods (though many women see this as an advantage!).
Visit your GP or local sexual health clinic to find out more about the IUS.
Contraceptive implant and injection
The contraceptive implant and injection are two long-term contraceptive alternatives to the IUS or pill. The implant is a small flexible rod (about 4cm in length) that is inserted under the skin of your upper arm, and releases a form of progesterone into your bloodstream, blocking pregnancy in the same manner as the POP or the IUS. The implant lasts for 3 years and can be taken out at any time.
There are two types of contraceptive injection, both of which contain a form of progesterone, and effectively prevent pregnancy. The Depo-Provera injection lasts for 12 weeks, and the Noristerat injection for 8 weeks. You cannot reverse the effects of the injection, meaning that if you have side effects they will last until the end of the 8 or 12 weeks, and sometimes longer.
As with the IUS, both the implant and the injection can lead to your periods stopping altogether.
Visit your GP or local sexual health clinic to find out more about the implant and injection.
Non-hormonal contraception methods (male and female)
IUD (Intrauterine device, or ‘coil’)
The IUD is very similar to the IUS. It is a small, T-shaped device that is inserted into the uterus. Unlike the IUS, however, it is non-hormonal and works by releasing copper instead of progesterone. There are different types of IUD, containing different amounts of copper, but they all work by stopping the sperm and egg from surviving in the uterus and fallopian tubes. The insertion of the IUD can be painful, and it can cause some changes to your periods (in some cases making them longer, heavier or more painful). However, if inserted correctly, the IUD is very effective form of contraception.
Natural family planning
One option for avoiding pregnancy is to work around your monthly cycle. The basic idea is that, with proper instruction from a trained expert, you are able to work out when you are most fertile. During this period you will either refrain from sex or use barrier methods of contraception. At other times of the month - when you are not as fertile - unprotected sex will be relatively risk-free.
If you want to try natural family planning, you will need proper instruction from a professional. Find more information at the Fertility UK website.
If you are looking to protect against pregnancy on a permanent basis, you might consider sterilisation. For women this involves having your fallopian tubes blocked or sealed whilst under general or local anaesthetic. The procedure comes with some risks, and - if ineffective - can lead to ectopic pregnancy. For men, sterilisation involves having a vasectomy, in which the tubes that carry sperm from the testicles to the penis are cut, blocked or sealed. A vasectomy is usually carried out under local anaesthetic and takes about 15 minutes. It is very effective in preventing pregnancy.
Both female and male sterilisation are very difficult to reverse, meaning you should be completely certain you do not wish to have children before you undertake such a procedure.
In the case of unprotected sex, you might consider seeking out emergency contraception. There are 2 types of emergency contraception: the emergency IUD, or coil, and the emergency ‘morning after’ pill. An emergency IUD must be fitted within 5 days of unprotected sex, and can be left in and used as long-term contraception after this. The morning after pill must be taken as soon as possible after unprotected sex to prevent pregnancy, and no later than 3 to 5 days (depending on the type of pill you take).
You can order the morning after pill for immediate or future use from our online Morning After Pill clinic. If you would like to be fitted with an IUD, you will have to visit your GP or local GUM clinic.
For more information, visit our Contraception Information page.