A vasectomy is a minor 15- to 30-minute operation usually carried out under local anaesthesia. It involves cutting the tubes that carry the sperm (vas deferens), and sealing them off with sutures or surgical clips. Recovery usually takes about two days, though patients are advised to avoid strenuous exercise for a week. There is normally a two-month wait after the surgery before the vasectomy can be confirmed, usually by a negative sperm result.

Vasectomies are free under the UK’s National Health Service, but can cost up to $1000 in the US. And changing your mind may be even more of a pain - costing up to £2200 in the UK and around $13,000 in the US.

What doctors tell you

* Inflammation of the testicles (orchiepididymitis), in one study, affected 4 per cent of vasectomy patients (Actas Urol Esp, 2004; 28: 175-214), and some 1 per cent also have bruising and swelling of the epididymis (Contracept Technol Update, 1990; 11: 185).

* Sperm granulomas, or pea-sized lumps of scar tissue in the scrotum, were seen in three of 30 vasectomised men (J Clin Ultrasound, 2004; 32: 394-8). They are usually not serious or painful, but they may require surgical removal.

* Chronic scrotal pain affects around one in seven (14.2 per cent) patients after vasectomy (BJU Int, 2004; 93: 571-4).

* Scrotal haematoma, a blood blister, is the most common immediate complication seen with vasectomy (Rajast Med J, 1972; 11: 51-61). It can affect up to 2 per cent of vasectomy patients (Contracept Technol Update, 1990; 11: 185), but should disappear within seven to 10 days.

* Impetigo is a contagious skin infection caused by bacteria - usually Staphylococcus aureus and/or group A beta-haemolytic streptococci (GABHS). Although infections are possible with any type of surgical trauma or skin wounds, it is unusual, especially in young fit men.

* Be aware of the psychological implications that may accompany sterilisation. It needs to be understood that the operation will prevent a man from fathering children, and the prospective patient needs to consider whether this fact will have a negative impact on his attitude towards his sexuality. In some cases, the patient is left feeling incomplete as a man after the operation. This can lead to unhappiness and a loss of libido.

What doctors don’t tell you The risks of these complications may be higher than doctors like to admit. One study involving 300 patients who had undergone a vasectomy concluded that the procedure was safe, despite reporting adverse effects in up to 18 per cent of the men. The reported problems included bleeding (ecchymoses, or little haemorrhagic patches), inflammation, gangrene (as a complication of infection), sepsis (infection) and endocarditis (an inflammation/infection of the endocardium - the inner lining of the heart and its valves - requiring antibiotics) (Actas Urol Esp, 2004; 28: 175-214).

* Chronic scrotal pain is the most common vasectomy complication: it may affect a third of patients - in one follow-up, four years after surgery (Br J Urol, 1992; 69: 188-91) - and have an adverse effect on the quality of life (J Urol, 1996; 155: 1284-6).

* Impetigo sepsis occurred in one out of the 300 vasectomised men in the study mentioned earlier and required hospitalisation (Actas Urol Esp, 2004; 28: 175-214).

* A possible link with prostate cancer is inconclusive, although vasectomised men may have an increased risk (Prostate Cancer Prostatic Dis, 2002; 5: 193-203). An expert panel recommended no changes in clinical practice due to inconsistent results across 16 reports (Contracept Technol Update, 1993; 14: 69-73). However, two studies found that sterilised men were almost twice as likely as their unsterilised counterparts to have prostate cancer (Consum Rep Health, 1994; 6: 8-9) and, more recently, Canadian retrospective data have suggested that such a risk is likely to increase after 10 years (Health Place, 2001; 7: 131-9).

* Post-vasectomy pain syndrome is recognised by some medical professionals, and involves epididymal congestion, tender sperm granuloma and/or nerve entrapment. Vasectomy reversal may be a possible cure (J Urol, 2000; 164: 1939-42).

* Erectile dysfunction (impotence) was put down to vasectomy in around 10 per cent of men in a Swiss study, with a reduced libido reported during the first two postoperative years in a further 22 per cent of cases (J Psychosom Res, 1994; 38: 759-62).

* Death, albeit rare, can result from vasectomy surgery. One study found that, out of 160,000 such operations, two resulted in death - one due to a scrotal haematoma, with death occurring as a result of infection; the other due to general anaesthesia (Contracept Technol Update, 1990; 11: 185).