Contraception is designed to ensure that sexual intercourse does not result in pregnancy. This fact sheet outlines the non-hormonal methods.
Non-hormonal contraception works by either preventing sperm fertilising an egg, or preventing the implantation of a fertilised egg into the lining of the womb. The main techniques are:
- Barrier methods
- Intra Uterine Devices (IUDs)
- Natural family planning
These are physical barriers that stop the sperm coming into contact with the egg, thereby preventing fertilization.
A condom is a thin, sheath usually made out of latex, which is rolled onto an erect penis before any sexual contact. Oil-based lubricants such as Vaseline should not be used with latex condoms because they can cause the latex to break down. Water-based lubricants, such as K-Y Jelly, and spermicidal creams or pessaries are safe. Oil-based lubricants do not affect condoms that are made from polyurethane.
Carefully follow the instructions that come with the condoms. After sex, you should check the condom for leaks and tears before its discarded (dont flush condoms down the toilet). If there is a problem, emergency contraception (the morning after pill), may be needed. For more information on this please see the factsheet on hormonal contraception.
If used according to the instructions, condoms are 98 per cent effective at preventing pregnancy. They may also protect both partners against certain sexually transmitted infections such as HIV and genital warts.
A female condom (Femidom) is a thin, soft polyurethane pouch, which is fitted inside the vagina before sex. It has an inner ring that goes into the upper part of the vagina, and an outer one, which should be visible. The female condom is less likely to tear than the male condom.
Carefully follow the instructions that come with the condom. If used according to the instructions, they are 95 percent effective.
The diaphragm and the cap
The diaphragm and cap are devices made of thin, soft rubber that are inserted into the upper part of the vagina to cover the cervix (neck of the womb). They act as a barrier to sperm.
Caps are smaller than diaphragms, but both are available in several types and sizes. In the first instance the cap or diaphragm needs to be fitted by a doctor or family planning nurse to make sure its the right size and is positioned correctly. After the initial fitting, they are put in place up to a few hours before sex. They need to be used with a spermicidal cream or pessary, and should be left in place for at least six hours after sex.
If used correctly, with spermicide, caps and diaphragms are 92-96 per cent effective at preventing pregnancy.
This is a small sponge impregnated with a spermicidal gel or cream. It is moistened with water before use, and then inserted high into the vagina to cover the cervix. It needs to be left in place for at least six hours after sex, and can be left for up to thirty hours, although there is a risk of infection if left in for longer than that.
This method offers 70 - 90 per cent protection.
These are creams, gels or pessaries (dissolvable tablets) that contain a chemical that kills sperm. You can use these to increase the effectiveness of barrier methods of contraception but do not provide reliable contraception when used alone. Spermicides can be bought without prescription at pharmacies. Some condoms have a coating of spermicidal lubricant.
The IUCD or coil
The intra-uterine contraceptive device (IUD) - or coil - is a small plastic and copper device, which is fitted into the womb by a doctor or nurse. It is designed to prevent the sperm meeting the egg, and may also make the egg move down the Fallopian tube more slowly and stop an egg settling in the womb.
The main advantage of a coil is that, once fitted, there is no need to worry about contraception. As long as the coil remains in place, it can be left for three to ten years. They are up to 98 per cent effective.
There are, however, disadvantages. Coils can make a womans periods heavier, longer or more painful. This may improve after a few months. Theres a small chance of getting an infection during the first 20 days after a coil is put in. Many doctors will advise a check-up for any existing infection before they fit one. Infection can spread to the womb and Fallopian tubes, and can possibly result in infertility. For this reason, a doctor may not recommend the coil unless the woman has already had any children she wants.
Its possible for the coil to be pushed out by the womb (expulsion) in the first few months after fitting. It has fine plastic threads, which pass into the vagina. The doctor or nurse will give advice on how to check the coil is still in place every month by feeling for the threads.
Rarely a coil might go through (perforate) the womb or cervix when it is fitted. This may cause pain but often there are no symptoms. If this happens, the coil may have to be located with an X-ray and removed in a small operation. Perforation is rare when a coil is fitted by an experienced doctor or nurse.
If pregnancy does occur while using a coil, there is a small risk of an ectopic pregnancy. This is when the pregnancy develops outside the womb, usually in a Fallopian tube. Although this is rare, it is dangerous. So, if you miss a period, see your doctor. An IUCD does not protect against sexually transmitted infections.
Natural family planning (NFP)
This involves reducing the chance of becoming pregnant by avoiding sex around the most fertile period during the womans monthly cycle. If the woman has a regular cycle, it can be 80-98% effective at preventing pregnancy.
The key is for the woman to keep a diary to work out when she ovulates - the part of the cycle where sex is most likely to result in pregnancy. It involves recording the dates of her periods for three to six months - taking day one as the first day of menstruation. Ovulation occurs around 12 -16 days before the start of the next period. The fertile period lasts for around eight or nine days around ovulation because although an egg only lives for 24 hours, sperm can survive in the womans body for up to seven days.
Measuring and recording body temperature with an accurate thermometer each morning can help determine when ovulation is occurring. After ovulation, body temperature can rise by between 0.2 and 0.6 degrees C. But a higher temperature can happen for other reasons, such as illness, so its not a failsafe indicator.
Cervical secretions also change during the monthly cycle, so the woman can monitor vaginal discharge. Early in the month, its scant and thick - it then becomes more watery as ovulation approaches. After ovulation the mucus returns to being thick and sticky once more. However, a vaginal infection can distort these patterns.
To find out more on natural family planning, contact your doctor or the Family Planning Association of Hong Kong. There are also devices available (Persona) that measure body temperature and hormone levels. If used according to the instructions, this is 94% effective.
The withdrawal method
This involves withdrawing the penis before ejaculation. This is not a reliable method because some sperm can leak out of the penis before ejaculation.
This is an operation to permanently prevent fertilisation. It is a permanent method of contraception and is only recommended for people who are sure they do not want to have any more children.
This is an operation performed under general anaesthetic, usually as day case surgery. The Fallopian tubes are cut, tied or blocked, often through keyhole surgery. The alternative is a hysterectomy, when the womb is removed.
In men - vasectomy
This is a minor operation usually performed under local anaesthetic. It involves cutting or tying the tubes (vas deferens) which carry sperm from the testicles to the penis.
The failure rate of sterilisation is around one in 2,000 for men, and about one in 200 for women, depending on the procedure. After a hysterectomy, pregnancy is impossible. These operations are not easily reversible, with attempts only 50 to 60 per cent successful.
This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional.
The Family Planning Association of HK
Tel : (852) 2575-4477
Fax : (852) 2572-2222
Kely Support Group
2/F, East Wing, 12, Borrett Road
Hotline: (852) 9032 9096 (English)
The Family Planning Association (UK)
Brook Advisory Centres
Planned Parenthood Federation of America
U. S. Food and Drug Administration