may be effected in many ways, and different methods are used in different cases. The manner of sterilising bedding, furniture, and the like, after contact with a case of infectious disease, is given under DISINFECTION; whilst the sterilisation of instruments, dressings, and skin surfaces, necessary before surgical procedures, is additionally referred to under ANTISEPTICS, ASEPSIS, and WOUNDS. For general purposes, one of the cheapest and most effective agents is boiling water or steam.

In women, this is performed by ligating (tying) and then cutting the FALLOPIAN TUBES – the tubes that carry the OVUM from the ovary (see OVARIES) to the UTERUS. Alternatively, the tubes may be sealed-off by means of plastic or silicone clips or rings. The technique is usually performed (by LAPAROSCOPY) through a small incision, or cut, in the lower abdominal wall. It has no effect on sexual or menstrual function and, unlike the comparable operation in men, it is immediately effective. The sterilisation is usually permanent (around 0·05 pregnancies occur for every 100 women years of use), but occasionally the two cut ends of the Fallopian tubes reunite, and pregnancy is then again possible. Removal of the uterus and/or the ovaries also sterilises a woman but such procedures are only used when there is some special reason, such as the presence of a tumour.

The operation for sterilising men is known as VASECTOMY.