By REBECCA WALSH
Mention "the snip" and most men are likely to grimace and look uncomfortable.
Despite that, New Zealand men have one of the highest vasectomy rates in the world.
About 18 per cent of adult males and more than 25 per cent of married men have had vasectomies.
The United Nations says male sterilisation accounts for only 7 per cent of contraceptive use worldwide.
Doctors say sterilisations are split 50:50 between men and women.
What is involved in a vasectomy or tubal ligation?
Dr Margaret Sparrow, a doctor at Wellington's Family Planning Association clinic, has been performing vasectomies since the mid-1970s.
The procedure she and many other doctors now use involves making a puncture wound near the base of the penis.
A small segment of the vas deferens - the duct that carries sperm from the testicles to the seminal vesicle - is removed and the ends are sealed.
The procedure, which causes less bleeding, infection and discomfort than the previous scalpel technique, is done under local anaesthetic and takes about 10-15 minutes.
Sperm is still produced, but when it gets to the break in the vas it has no where to go and the body absorbs it.
Dr Sparrow recommends men take the day off work and don't do anything too strenuous - such as lifting, digging or mowing the lawns - for about a week.
She does not make any restrictions on sex. Some men feel uncomfortable for the first 48 hours, she says, but "some people are anxious to make sure everything is still working properly".
A vasectomy does not work immediately, and other forms of contraception should be used until a semen test three months after the operation is clear.
In about one in 400 cases, the initial test may find active sperm and the surgery may have to be repeated.
There is a late failure rate of between one in 1000 and one in 2000.
Overseas reports in the 1990s suggested a link between vasectomy and prostate cancer. But this has not been supported by subsequent studies, including research done at Otago University.
Dr Charlotte Paul, an associate professor in the university's department of preventive and social medicine, says one study, published in the Journal of the American Medical Association in June, found having a vasectomy did not increase the risk of prostate cancer, even after 25 years or more.
The average cost of a vasectomy is about $350.
It is less invasive and less expensive than a tubal ligation for women, which can cost up to $1500.
A tubal ligation works immediately, but requires a general anaesthetic and a hospital stay.
Dr Cindy Farquhar, clinical director of gynaecology at National Women's Hospital, says the operation involves blocking or closing the fallopian tubes close to the entry of the uterus.
It is performed by laparoscopy, in which a hollow needle is inserted into the abdomen and the cavity is inflated with gas.
As with any surgery involving sharp instruments in the abdominal cavity there is a risk of damage to the bowel, bladder or blood vessels.
Dr Farquhar says a tubal ligation is generally a day-stay procedure with three days of convalescence.
It has a failure rate of about one in 200.
Who chooses sterilisation?
In most cases, men or women who have had a family and are sure they do not want any more children.
"The typical vasectomy person is a man in his 30s," says Dr Sparrow.
"He's got two children, is happily married and they have decided they don't want any more children. The younger child is out of the danger period, which is the first year of life.
"We are very reluctant to do it on a young person as they can change their mind."
Dr Farquhar says National Women's Hospital generally does not perform tubal ligation on women under 25.
"We hope they would have had at least two children. Generally it's women in their 30s, but every so often we get a woman who is 25."
A survey by Waikato University researchers in 1995 found tubal ligation is more common in Maori women, whose partners are less likely to have a vasectomy.
Twenty per cent of Maori women aged between 35 and 39 had tubal ligations, compared to 12 per cent of non-Maori women.
Figures for the same age group showed 14 per cent of Maori women had a partner who had a vasectomy compared to 21 per cent for non-Maori.
Dr Ian Pool, professor of demography at Waikato University and one of the authors of the book New Zealand's Contraceptive Revolutions, says New Zealanders embraced sterilisation in the 1970s, but rates have since dropped as a result of delayed child bearing.
Figures from the 1995 survey show that by age 40, nearly 60 per cent of women born in the 1940s, or their partners, were sterilised.
For those born in the 1950s and early 1960s, the sterilisation rate dropped to 50 per cent.
Do people ever have regrets?
An Australian study found women who have their tubes tied often regret the decision and end up seeking in vitro fertilisation (IVF) treatment.
Researchers from Hornsby and Royal North Shore hospitals found those who had a tubal ligation immediately after a caesarean were most likely to have second thoughts.
The study, reported in the Australian and New Zealand Journal of Obstetrics and Gynaecology, says 66 per cent of sterilised women who sought IVF had changed partners after the tubal ligation.
Although vasectomies and tubal ligations can be reversed, doctors say they should be regarded as permanent.
Dr Sparrow says about 1 or 2 per cent of men choose to reverse a vasectomy.
If the reversal is done within 10 years, the chance of conceiving drops to about 85 per cent, but other factors include the woman's age and fertility.
People also have the option of taking out "insurance" - they can pay to have the man's sperm stored and frozen "just in case anything happens".
Herald feature: Health
By REBECCA WALSH