Q: Our family is complete and my husband has offered to have the snip so that I can come off the Pill. But does a vasectomy have any long-term side-effects?

A: Sterilisation, either male or female, is a sensible choice for couples in your position and one of the most popular methods of contraception among over 35s.

Vasectomy is usually done under local anaesthetic through two tiny cuts in the scrotum, and involves cutting and tying off the tubes (vas deferens) that carry sperm away from the testicles.

There has been some concern that vasectomy may slightly increase the risk of cancer of the prostate and testicle, but the evidence is conflicting and is of no real significance.

A lot of men worry that vasectomy will affect their virility, a concern compounded by numerous old wives' tales. The truth is that it has no effect on a man's hormone levels, his sex drive or his performance in bed. And vasectomised men still ejaculate when they reach orgasm, but the fluid doesn't contain any sperm (once their stores have been exhausted - something that can take a few months after surgery).

The operation can be reversed, but success rates vary and vasectomy should be regarded as permanent and irreversible. It's not foolproof, though. The vas deferens can sometimes reconnect itself and there is a failure rate of around 1 in 1,000, but don't let it put you off; it is still far more effective than any other form of contraception, including the Pill.

There are alternatives, including options that mean you needn't have any more periods (such as the intra-uterine system Mirena). Visit www.fpa.org.uk for a review of all your options.

E-mail your questions to drmark@thetimes.co.uk