It's reliable, cost-effective and has few side-effects. Why don't more GPs promote vasectomy, asks William Hartston
"Just a little prick," the doctor said as he concentrated on my freshly shaved genitalia. The remark struck me as insensitive as he prepared to render my scrotal environs insensate, but I suppose he gave a good many local anaesthetics, all of them just little pricks, and relatively few prior to a vasectomy.

The idea of taking a knife to my vas deferens was originally my wife's (it's usually the woman who suggests the operation, said the nurse at the Margaret Pyke centre where we went for counselling). The vas (from the Latin for vessel) is the tube bearing (deferens - present participle of deferentio, I bear) sperm from the testes towards the world outside; and the -ectomy (Greek: ek, out; tome, cut) snips a bit out of their escape route. Anyway, apart from my purely etymological objections to mixing Latin and Greek roots, I agreed that a vasectomy was, in principle, a good idea. Fifteen years on the pill and two trips to the maternity ward were enough. Now it was my turn.

That was three years ago. Well, as our GP had said, it's not good to rush such things. A vasectomy, he warned, while perfectly safe and simple, can damage a man's psychological well-being. Not as much as an unwanted pregnancy, I thought, but I agreed that it was wise to wait a few months to be certain that my wife would not change her mind about not wanting any more children.

She didn't, so I decided, after 36 months, that it was time to be brave.

The GP this time was less discouraging (though I am sure his legs became progressively more tightly crossed as he explained the details to me). But he thought it wasn't available on the NHS, and he was unsure how to make the necessary arrangements. Three phone calls later, however, he discovered that the Margaret Pyke centre, just off Tottenham Court Road, had a deal with the Islington and Bloomsbury Health Authorities to perform vasectomies on the NHS.

A month later, my wife and I arrived there for the counselling session. They insisted on speaking to both of us. They left us alone together in a waiting room with a noticeboard full of pictures of mothers and babies. If deliberate, it would have been a brilliant psychological ploy to give us a last chance to change our minds, but the true explanation was less devious: across the hall from the vasectomies is the fertility clinic.

The nurse interviewed us to make sure we knew what we were doing and were aware of the risks - a recent study claims considerably higher death rates from testicular cancer in vasectomised males who are over 75, though whether there is a causal connection is a matter of considerable debate. She also stressed the essential irreversibility of the operation - only about 50 per cent of attempted reversals succeed and if left too long, there is no chance of success at all. Was I certain, she asked, that even if the worst were to happen I would not want to have another child? I was certain.

The operation - a fortnight later in my case - took less than 15 minutes under local anaesthetic. The surgeon finds the vas and manoeuvres it to the front of the scrotum (which I had shaved, very carefully, the night before). I should, for the purposes of writing a diligently researched piece, have been watching closely at that stage, but instead lay back and chatted somewhat nervously with the surgeon about Aristotle's view that one testicle produces boy babies and the other girls. By the time he had told me that some of his patients actually believed that, he had done the boy half and was finding vas number two for the girls. A specially designed clamp holds, punctures and snips, then two stitches and the whole thing was done.

It will now take up to five months before we can bid farewell to the contraceptive pills. There is a reservoir of sperm that must be exhausted before the effect of the vasectomy is total. "You should make love on a regular basis," advised the nurse, in order to speed the process. That cuts out the rockery and waterbed, I suppose.

She handed me two specimen bottles with an address to return them to at the beginning of April. It had all been explained by the nurse at the counselling session: two sperm samples are required a fortnight apart. "Because it is important they are not contaminated, I'm afraid they have to be produced by masturbation," she explained. "We'll provide full instructions."

The instructions, I was relieved to hear, were for screwing the lid on the bottle.

I am writing this 10 days after the operation. Apart from a slight tenderness, mild swelling and extreme caution whenever our three-year-old rushes towards me, there has been surprisingly little discomfort. The stitches will fall out or dissolve in another week or so and everything will be back to full working order. With no obstruction to the normal flow of seminal fluid, even my closest friends will be unable to detect any difference.

Nobody knows precisely how many vasectomies are performed annually in Britain. The Family Planning Association estimates 80,000. The average age of the patient is around 37. With a cost to the NHS of around pounds 70 (at least pounds 200 if done privately), it is the same price as a constant supply of contraceptive pills for between four and 10 years. Vasectomy is therefore cost-effective, generally reliable (a spontaneous repair appears to happen in about 0.5 per cent of cases) and relatively free of side-effects. If my experience is in any way typical, it really ought to be promoted more actively by general practitioners.