By Clare Murphy
Health reporter, BBC News
Second marriages or starting afresh with a new partner mean a number of men are spending large sums of money trying to reverse their vasectomies.
Vasectomies involve cutting the tube which carries sperm from the testes
Vasectomy is more popular in the UK than almost anywhere else - some 16% of men under 70 have had one, and rates have remained consistent.
But remarriages now account for nearly 40% of weddings, and the decision to have the 'snip' can come to be bitterly regretted.
However reversals are all but banned on the NHS: they can be costly to obtain privately and success is not guaranteed.
The government imposed a blanket ban on vasectomy reversals in 2004 after high demands for the operation put pressure on NHS services.
It said that the procedures would still be allowed in "exceptional circumstances", left to be determined by individual health trusts.
But the case of a Staffordshire man last year who had lost his young son to cancer yet was still refused a reversal was seen as highlighting the extent of rationing.
"If you are going to put it in terms of cancer drugs versus vasectomy reversals it's not hard to see which should win," says Dr Sam Nag, a retired NHS consultant who still carries out reversals for the British Pregnancy Advisory Service (BPAS).
"But if the NHS is going to offer vasectomies - and it should, as this is a cost effective and efficient way of preventing pregnancy - then there should be funding of reversals.
"People's lives can change dramatically - we should accept that rather than adopting this 'you made your bed now lie in it' attitude."
Taking home baby
A private reversal can cost up to £3,000.
The procedure involves reconnecting the tubes - or vas - that carry the sperm from the testes to the penis, which were cut as part of the original vasectomy.
The chances of rejoining the tubes is around 80%, and one technique even has a 90% success rate.
However the chances of ending up with a baby are less - around 55% if the operation is performed within 10 years of the vasectomy, and just 25% if it has been longer.
Sperm quality can be poor and in some cases vasectomised men start to produce antibodies against their own sperm, making them incapable of fertilising an egg after reversal.
Despite the problems, clinics report business is brisk on the reversal front.
Spire Healthcare - the new name for the 25 former Bupa Hospitals - says it has consistently performed an average of three times more vasectomy reversals than vasectomies.
Dr Andrew Dawson runs a reversals clinic in Hartlepool, carrying out 200 procedures each year.
He says the credit crunch has yet to dampen the number of inquiries and is currently running a four month waiting list.
"We see many people with second wives who had two or three children in a previous relationship and thought they were done, only for their marriage to break down," he says.
"But there are also some couples who change their mind about more children at key moments - such as when their children go off to school, or university.
"I don't believe more counselling at the time of the original vasectomy is the answer - for most people that decision was the right one for them at that time."
While reversals can be undone, experts advise men should treat it as an irreversible process when making the decision.
There are certain IVF techniques which can extract sperm from the testes of a vasectomised man, but these may be even more expensive than a reversal with an even lower success rate.
Dr Allan Pacey, senior lecturer in andrology at Sheffield University and secretary of the British Fertility Society, advises those set on a vasectomy to consider freezing some sperm before the operation.
"I do see men for whom reversal has not worked who say 'if only I'd known I could store some sperm'.
"The problem is you're asking a man to foresee a future where he might not necessarily be with his current partner - and that may be quite hard to do when she's sitting next to you."