* No-scalpel vasectomy is becoming the operation of choice as postsurgical complications (such as haematoma, bleeding or infections) are much less likely. Instead of a knife, the technique uses a small clamp, pointed at each end, to pierce the scrotal skin.
* Fascial interposition, where the sperm-duct sheath is pulled over one cut end to seal the incision, improves the outcome even more, especially if used with cautery (BMC Med, 2004; 2: 21).
* Condoms may be 98-per-cent effective without spermicide, and are now available without the vaginal-damaging nonoxynol-9 and so are less likely to provoke side-effects. Made of latex (rubber), polyurethane plastic and even lambskin, the German company Condomi even makes some that are suitable for vegans (www.condomi.com), using cocoa powder (BBC News, 1999; April 16). Traditional latex-condom manufacture uses casein, a milk protein.
* Natural Family Planning (NFP), used correctly, is more effective than the condom or cap/diaphragm (Adv Contracept, 1999; 15: 69-83; www.fpa.org.uk). It involves being aware of your partner's cycle, helping her identify and avoiding her fertile time, and abstaining during unsafe days. Fertility Awareness is similar, but advocates a barrier method for unsafe days. Both require discipline, organisation and cooperation.
* Spermicides (see www.vasectomymedical.com/birth-control.html), usually used by the woman, only afford 80-per-cent protection.
* Vasclip, available in the US, is a tiny plastic device the size of a grain of rice that clips the sperm ducts shut. Costing around $400-500, it is touted as a gentler alternative as it doesn't cut or burn, thus reducing complications such as swelling and infection (www.vasclip.com). It is also said to be reversible.
* Non-hormonal oral contraceptives for men. In 1998, a review by the World Health Organization concluded that trials of such contraceptives be abandoned. Nevertheless, some groups continued to carry on with their research. In one such trial using the cotton-plant toxin gossypol on 8000 Chinese men, the side-effects included sterility and hyperkalaemia (abnormally low potassium) (Asian J Androl, 2000; 2: 283-7).
In 2001, scientists discovered a calcium channel in the sperm's tail. If the right molecules can be found to block this channel, blocking sperm activity, the result could be a pill that either partner could take before sex to induce temporary infertility (Lancet, 2001; 358 [online]). But until such a breakthrough is made safely, men's contraceptive choices are limited.