Attempts to find some way of having sex without producing babies have a long history. Documents from Mesopotamia, 4000 years ago, record that a plug of dung was placed in the woman’s vagina to stop conception. In Cleopatra’s Egypt, small gold trinkets were inserted into the uterus of the courtesans as a form of early intrauterine contraceptive device. At the same time, camel herders pushed pebbles into the wombs of the female camels so that they would not get pregnant on long caravan treks. More recently, in the eighteenth century in France, the renowned philanderer Casanova used a thin pig’s bladder as an early condom or “French letter”. Prior to this there were similar devices made from leather or gut. Finding a safe, effective and reliable contraceptive has proved a difficult task.
Today, a very wide range of safe and effective contraceptives is available. They include :-
Available since 1962, the contraceptive pill has revolutionised modern life. It is probably the safest and most effective form of reversible contraception. There are many different dosage forms and strengths, so that most women can find one that meets their needs. The main types are the monophasic (constant dose) two-hormone pill, the biphasic (two phase) and triphasic (three phase) hormone pills in which the hormone doses vary during the month, and the one hormone mini-pill.
The morning-after pill is a short course of a high dose of sex hormones (often an oral contraceptive), which must be taken within 72 hours of sexual intercourse. Two doses are taken twelve hours apart and they are often given with a second medication to prevent vomiting, which is the most common side effect.
Only introduced in 2002, patches containing the progestogen hormone norelgestren can be used on a weekly basis to prevent ovulation. Users must take other precautions against pregnancy if the patch falls off, or is left on for more than a week.
Medroxyprogesterone injections are a means of contraception in which a synthetic form of the female sex hormone progesterone is injected, causing the ovaries to stop producing eggs. One injection lasts for 12 weeks or more depending on the dose given.
It is possible to have a small rod shaped, hormone containing implant inserted into the flesh on the inside of the upper arm (Implanon). This gives almost 100% protection against pregnancy for three years. In most women, their periods cease for this time, but in some, irregular bleeding leads to the implant being removed. It is essential for the implant to be removed after the three year period. An earlier system (Norplant) used six small rods implanted under the skin in a similar way.
Spermicides are creams, foams, gels and tablets that act to kill sperm on contact. A spermicide must be inserted no more than 20 minutes before intercourse and a new application must be used before each ejaculation. Generally the use of spermicides is advised with a diaphragm or condom. The most commonly used spermicide is nonoxynol 9.
The condom is the simplest barrier method of artificial contraception. A condom is a thin rubber sheath, which is placed on the penis before penetration. When the man ejaculates, the sperm are held in the rubber tip. There is also a female version of the condom, which is a thin rubber or plastic pouch that is inserted into the vagina.
The diaphragm for women works on a similar principle as the condom in that it provides a physical barrier to the sperm meeting the egg. A diaphragm is a rubber dome with a flexible spring rim. It is inserted into the vagina before intercourse, so that it covers the cervix. It is best used with a spermicidal cream or jelly to kill any sperm that manage to wriggle around the edges.
Like the diaphragm, the cervical cap is a barrier method of contraception, but it is much smaller because it fits tightly over the cervix, rather than filling the vagina. The cap must be fitted very carefully and should be used with spermicides.
A contraceptive sponge is impregnated with spermicide and is inserted into the vagina so that it expands to cover the cervix. Like a diaphragm it is inserted before intercourse but is disposable and thrown away after use.
The IUD is a piece of plastic shaped like a T, that is impregnated with a hormone. It is inserted by a doctor through the vagina and cervix to sit inside the uterus (womb). The device can remain in place for up to five years before its needs to be changed.
NATURAL FAMILY PLANNING:
Natural family planning is a form of periodic abstinence from sex (not having sex at those times of the month when a woman is fertile). The trick is knowing just what are the safe and not so safe times. Obviously, it is essential for both sexual partners in this situation to co-operate fully in the contraceptive process. The man must be as aware of the woman’s cycle as she is herself. For this reason alone, this method of contraception does not suit all couples.
A tubal ligation (having the tubes tied, clipped or blocked) is an operation that usually renders a woman permanently unable to have children. As a contraceptive it is almost 100% effective, but as with all surgical procedures, failures may occur, and women should be aware of this when they have the procedure.
A vasectomy is procedure in which the vas deferens (sperm tubes) of a man are cut and tied or clipped in order to prevent him from fathering children. It is a simpler operation than the sterilisation (tubal ligation) of a woman. It should be considered to be a permanent procedure at the time it is performed, but there is always a small risk that the cut sperm tubes may spontaneously reconnect at a later time making the man fertile again.
Contraceptive effectiveness varies significantly between these various methods. The effectiveness is measured by the percentage of women who would be expected to fall pregnant after using a method while having regular sexual intercourse for a year. The effectiveness of most methods is listed in the following table:-
Effectiveness Of Contraceptive Methods
|Method||Failure Rate %|
|Withdrawal (coitus interuptus)||20|
|Diaphragm with spermicide||18|
|Natural family planning||12|
|Contraceptive vaginal ring||2|
|Progestogen implant (Implanon)||0.3|