The Sheath Method Contraception

The sheath is a tube with one closed end, which is worn over the penis during sex to trap the sperm and prevent them from entering the woman’s vagina. Sheaths are also commonly called condoms, rubbers, skins, French letters and Durex (after one of the main brand names).

The first sheath was described by Fallopius in 1565 — he developed a linen bag for protection against syphilis. The famous lover Casanova popularized sheaths, but they did not become readily available until the discovery of vulcanized rubber in the mid nineteenth century. Up till then, sheaths had mostly been made of animal intestine or skin. The wider use of sheaths and coitus interruptus in Britain at the end of the nineteenth century probably accounted in part for the drop in the birth rate at that time.

Modern sheaths are generally made of rubber (although a small number are manufactured from animal collagen), and modern technology means that the rubber can now be very thin indeed. There is very strict quality control for sheaths manufactured in this country; they are checked rigorously for flaws or for weakness, and must conform to British Standard 3704 (look for the kite mark on the packet!).

Sheaths can be obtained in various shapes — ribbed, plain, teat-ended etc. They are all a standard size, approximately seven inches long, as they can expand so much (up to six times their original size). Some sheaths are pre-lubricated; these are claimed to increase the man’s sensitivity. Some brands are advertised as being spermicidal; these contain a small amount of spermicide in the lubricant. The Which? Guide to Birth Control says ‘this may provide some extra protection, but is unlikely to be quite as effective as a traditional spermicide used together with an ordinary condom’.

Sheaths are generally packed in foil, which keeps them in good condition; if stored away from heat, humidity and friction they have a ‘shelf-life’ of several years. However, excessive heat or humidity can cause the rubber or package to deteriorate. Similarly, carrying a sheath around in a pocket or wallet for very long can damage the packaging with a similar result. Sheaths should never be lubricated with petroleum jelly, as this damages the rubber; if you require extra lubrication, use KY jelly.

The sheath is one contraceptive which has to be fitted at the time of sex, as it has to be fitted on an erect penis. Before any penis/vagina contact, remove the sheath from the packet. Unroll the first inch; if the sheath does not already have a teat end to catch the sperm, pinch the end with the thumb and forefinger. This will leave an empty pocket to hold the sperm, and will also help prevent any possibility of bursting. Unroll the sheath fully onto the erect penis — this can be done by the man or the woman; if it is not fully unrolled, semen may seep out of the bottom of the sheath. Make sure that you do not damage the rubber with your fingernails as you unroll it. The sheath must be put on before any contact with the vagina, as even the drops of lubricating fluid produced by the penis before ejaculation contain many sperm. After ejaculation, and before your erection subsides, hold the sheath close to the penis with your fingers and withdraw both carefully from the vagina, making sure that no semen escapes.

Advantages

Over 2 million men in Britain use the sheath regularly. There are many advantages; for instance, sheaths are easily available over-the-counter, and do not need any fitting or prescription by a doctor. Indeed many large chemists’ now have sheaths on display at the counter so that customers can serve themselves and just present the goods for payment rather than having to ask for them. Obtained in this way they are fairly cheap; they can be bought even more cheaply by mail-order in bulk. Family planning clinics can provide sheaths free of charge, but they cannot be obtained on prescription from your GP.

As far as can be determined, sheaths produce no serious physical side-effects for either partner, or for any baby conceived accidentally if the method fails. In addition, they help prevent the spread of some forms of VD. There is also evidence that use of the sheath (or cap) helps protect the woman from cervical cancer; recent research suggests that this condition is triggered off by frequent exposure of the cervix to semen (especially that of multiple partners). The sheath prevents the semen from ever reaching the vagina.

In these days of more openness about sex, sexuality and contraception, the sheath provides a form of contraception which both partners can take part in using — many couples incorporate putting on the sheath into their foreplay before intercourse. And, of course, one of the main benefits is that used conscientiously, especially with a spermicide, the sheath has a good success rate as a contraceptive.

Disadvantages

Some of the main disadvantages of the sheath are that the couple always needs to be prepared for intercourse, and that putting on the sheath must always be done at the time of sex, which may reduce the spontaneity of lovemaking. Consequently this is not a good method to use if you or your partner are embarrassed over sex or contraception, as it is very difficult to put on a sheath and apply spermicide unobtrusively. Sheaths can be slightly embarrassing to purchase and carry around, although probably no worse than spermicide or the pill. The sheath is the only reliable nonmedical contraceptive that gives responsibility to the man and there is no doubt that many men don’t want to take this responsibility.

Most men find that even the best sheath dulls their sensitivity somewhat. The degree varies. For some men it makes sex with a sheath unacceptable; for others it is no particular problem, and for those who suffer from premature ejaculation it can be a positive advantage. Some women may also find their sensitivity during lovemaking decreased. Another disadvantage is the need to withdraw the penis and sheath as soon as intercourse is over — this can bring the intimacy of lovemaking to a rather abrupt end. Disposal of the sheath can be a problem, as they tend to block the drains if flushed away; throwing them away with the rubbish is preferable.

A few men and women develop allergies to compounds in the rubber or the lubricant of sheaths. This can often be remedied by switching to another brand, or by using the more expensive collagen sheaths. Another problem that many people find difficult to overcome is that sheaths still have a slightly furtive, squalid aura about their use. This feeling is quite unnecessary in the modern day, when sheaths are a respected and reliable contraceptive. In other countries the sheath has no such associations; it is estimated that in Japan, four out of every five men use sheaths as their regular contraceptive.

Reliability

Sheaths should ideally be used with a spermicide as this makes them far more reliable. If used this way, the woman should insert a suitable spermicide (preferably foam) about ten minutes before intercourse. If used with foam, the theoretical failure rate can be as low as 1 per user/year (2-3 without spermicide). The actual failure rate is more like 5 per user/year with spermicide and approximately 10 with-

out. The three largest surveys of sheath use had failure rates of 11, 14 and 14.9; smaller studies have varied from 3 to 36(!).

One reason for failures of this contraceptive method is poor quality sheaths; not all the sheaths on sale in this country are manufactured here, and so may not conform to our stringent standards. However, the most common reason for failure is intermittent use, or when the couple decides to take a risk rather than interrupt the spontaneity of lovemaking. Once again, statistics vary a great deal according to the care and commitment of the users.

Conclusions

Used conscientiously in conjunction with a spermicide, the sheath is a reliable contraceptive with a good success rate. It is also very good for intermittent use, for instance to cover the ‘unsafe’ days in the rhythm methods, after childbirth, while the woman is changing contraceptive methods, as a back-up when a woman has forgotten to take a pill, or when a man is waiting for the ‘all-clear’ after a vasectomy. It is best used by couples who are fully at ease with their own and each other’s bodies, who have little or no embarrassment about obtaining and using it, who do not find it aesthetically unacceptable, and who experience no physical problems (e.g. allergy, lack of sensitivity) with the method.