What contraceptive options are available for females
There are both hormone and non-hormone-based contraceptive options available for women to use.
How do non-hormonal contraceptives work?
Barrier methods physically prevent sperm from entering the womb (uterus) and fertilising an egg (ova). They are either worn on the male’s penis (condoms) or inserted into the female’s vagina (internal condoms, diaphragms and caps). Condoms are the only method of contraception which will also protect against sexually transmitted infections.
The copper intra-uterine device (also known as the copper coil) is another non-hormonal contraceptive option. It is a small plastic T-shaped device covered in copper wire or copper bands which is inserted into the uterus. Copper has toxic effects on the sperm and the egg.
How do hormonal contraceptives work?
Hormonal contraceptives contain synthetic versions of naturally occurring female sex hormones – either:
- Combination of oestrogen and progestogen (combined contraceptives
- Progestogen-only.
Combined contraceptives stop the normal process of an egg being released from the ovary (ovulation). The oestrogen and progestogen contained in combined contraceptives have a negative feedback effect and reduce the release of follicle-stimulating hormone (FSH) and luteinising hormone (LH) from the pituitary gland. FSH and LH normally stimulate the ovaries and so with their production reduced ovulation cannot occur. The progestogen component increases viscosity (thickness) of mucus in the neck of the womb (cervix) to make it more difficult for sperm to reach the uterus and fertilise an egg. Progestogens also limit growth of the uterine lining (the endometrium) which makes it less likely that a fertilised egg can attach and develop into a pregnancy.
Combined contraceptives are available as:
- Oral pills
- Patches that are worn on the skin
- Rings that are inserted into the vagina.
Progestogen-only contraceptives primarily alter the viscosity of the cervical mucus and inhibit growth of the uterine lining. Depending on the type of progesterone-only contraception, it may also inhibit the release of an egg from the ovary so that it happens less frequently or not at all.
Progestogen-only contraceptives can be delivered using:
- Oral pills
- Injections into muscles
- Implants under the skin
- Intra-uterine device, also known as the hormonal coil (a small plastic T-shaped device inserted into the uterus)
Are there any benefits to hormonal contraceptives?
For women who experience irregular periods, hormonal contraceptives can be used to make periods more regular or predictable.
Hormonal contraceptives can result in lighter and less painful periods. Women with particularly heavy or painful periods may therefore be recommended hormonal contraceptives for this purpose.
Combined hormonal contraceptives may also improve symptoms that are related to periods such as pain and headaches.
Combined hormonal contraceptives can help with the symptoms of several other medical conditions including premenstrual syndrome, polycystic ovary syndrome, endometriosis and severe acne. Progestogen-only contraception may also help with endometriosis.
Taking combined hormonal contraception can also reduce the risk of getting ovarian cancer and womb (uterine) cancer.
What are the side effects and risks to contraceptives?
Reported side effects of combined hormonal contraception include:
- Headaches
- Feeling sick (nausea)
- Sore breasts
- Mood changes/depression
Reported side effects of progestogen-only contraceptives:
- Acne
- Mood changes
- Weight gain
- Changes to sex drive (libido)
- Headaches
- Sore breasts
Currently there is not enough evidence to say whether these side effects are directly caused by taking hormonal contraception. Side effects usually improve within three months of use.
Hormonal contraceptives can cause various changes in period bleeding patterns or bleeding between periods (breakthrough bleeding), especially in the first three months of starting.
Copper intra-uterine devices may cause periods to become longer, heavier or more painful but this usually improves after a few months.
What are the potential risks of using contraceptives?
Combined hormonal contraception can cause high blood pressure in a small number of people. There is a very small increase in risk of heart attack or stroke. There is also a very low risk of developing blood clots in 1 in 1,000 people (Lidegaard, et al.). Therefore, other methods of contraception will need to be considered if there are other additional factors contributing to this risk.
There is a slight increased risk of developing breast cancer or cervical (neck of the womb) cancer whilst using combined hormonal contraception and the progestogen contraceptive injection, however this risk reduces after stopping use. There may also be a possible link between the progestogen-only pill use and breast cancer but the evidence for this is limited and the risk would be very small.
With progestogen-only contraception there is a chance of developing fluid filled sacs in the ovaries (ovarian cysts) although these often disappear without treatment.
The progestogen contraceptive implant is very safe but there is a risk of infection at the implant site or the implant moving out of place.
The progestogen contraceptive injection can cause bones to become weaker if used for more than one year, but bone is likely to recover after stopping.
Intra-uterine devices have specific side effects and rare risks. After being inserted they may cause period-like pain or bleeding (spotting). There is a risk of pelvic infection, usually within three weeks of having the device inserted. The device may move, come out or cause damage to the womb. Furthermore, if the contraceptive fails and pregnancy occurs, there is a risk that it could develop outside of the womb (ectopic pregnancy).
How effective is hormonal contraception?
Hormonal contraception is over 99% effective if used as instructed (NHS England). Hormonal intra-uterine devices need to be replaced every three to eight years depending on the brand used. The progestogen-only implant must be replaced every three years, and the progestogen-only injection lasts for eight to 13 weeks before it needs to be repeated. Contraceptive pills, patches and vaginal rings are often less effective as they rely on the user remembering to take or change them correctly. Oral contraceptive pills may be less effective under certain circumstances, such as if the person is experiencing diarrhoea and/or vomiting. How effective hormonal contraceptives are can also be affected by other medications being taken. In these circumstances additional precautions such as using barrier protection should be taken.
Are there any long-lasting effects after stopping contraception?
When you stop taking hormonal contraceptive pills, the chance of getting pregnant usually returns to normal within one month. For the contraceptive patch and vaginal ring this is one to three months. For the implant and intra-uterine system, the chance of getting pregnant returns to normal as soon as it is removed. When stopping the contraceptive injection, it can take up to one year for the chance of getting pregnant to return to normal.
For all non-hormonal methods of contraception, as soon as they are not used the chance of getting pregnant returns to normal.
What is emergency contraception?
Emergency contraception refers to an intervention to prevent unintended pregnancy following either sexual intercourse without contraception or where contraception has failed. There are both hormonal and non-hormonal options for emergency contraception.
The copper intra-uterine device is a non-hormonal option of emergency contraception and can be inserted within five days of unprotected sexual intercourse. Even if the egg has been fertilised, the presence of the copper intra-uterine device causes inflammation in the lining of the womb (endometrium) to prevent the fertilised egg from attaching to the endometrium. Therefore, the copper intra-uterine device can be used after ovulation (release of an egg from the ovary) but only within five days. The device can then be left in as a long-term method of contraception – it is over 99% effective and lasts for five to ten years.
There are two hormone-based options of emergency contraception which are given as a one-off tablet. However, neither of these are effective after ovulation has happened as they work by delaying ovulation by five days, the amount of time that sperm can survive and still fertilise an egg. They also do not provide long term contraception.
Ulipristal acetate is a medication that acts on specific targets of the sex hormone progestogen and prevents ovulation. It does this by suppressing the surge of LH release which triggers ovulation. Even if the LH surge which triggers ovulation has started, ulipristal acetate can still delay ovulation by postponing the release of the egg from the fluid-filled sac (follicle) that contains it in the ovary. It can be used up to five days after unprotected sexual intercourse.
Levonorgesterel is a type of progestogen which also inhibits ovulation but unlike ulipristal acetate it is not effective once the LH surge has started. It can be used up to three days after unprotected sexual intercourse.
Which option is suitable depends on the point in the menstrual cycle when it is needed and any other medications that are being taken. The sooner it is used, the more effective it will be at preventing unintended pregnancy following unprotected sexual intercourse.