them sterile. My response to this is to inform them that the behaviour most likely to make women sterile is having sexual intercourse without the use of condoms.

Birth control pills, injections and other contraceptive devices do not lead to sterility. They simply protect a woman from pregnancy during the time they are in use. However, acquiring sexually transmitted infections like Chlamydia or Gonorrhea through unprotected intercourse can lead to Pelvic Inflammatory Disease (PID). This is the most common preventable cause of infertility in women.

Pelvic Inflammatory Disease is the phrase used to describe the destructive process that occurs in the female reproductive organs (located in the pelvis) after they have become infected with bacteria and/or the Chlamydia organism.

Most cases of PID result from infection with Chlamydia or Gonorrhea, but other bacteria can be involved. PID develops when these sexually transmitted organisms are deposited in the vagina during unprotected sexual intercourse.

The organisms make their way into the cervix (mouth of the uterus or womb) and into the uterus, fallopian tubes and ovaries. This migration occurs especially well during the woman's menstrual period, and so it is common for symptoms of PID to occur just before or after menstruation.

Once deep within the pelvic reproductive structures, harmful organisms inflame these tissues causing them to swell and develop fluid and pus accumulations.

This can lead to pelvic pain, fever, odorous vaginal discharge, irregular vaginal bleeding, nausea and vomiting in the acute stages of the disease.

Ultimately this inflammatory process can lead to scarring of the pelvic tissues causing chronic pelvic pain and blockage of the fallopian tubes. The likely result of fallopian tube blockage is infertility. Each occurrence of a pelvic infection doubles a woman's chances of having a fertility problem.

Scar tissue in the fallopian tubes also greatly increases the risk of ectopic (or tubal) pregnancy since a fertilised egg cannot make its way from the fallopian tube into the uterus to implant. Ectopic pregnancy is a life-threatening complication of PID.

While the symptoms of PID can sometimes be very dramatic, causing the woman to seek medical care, almost 50 percent of women with pelvic infections have little or no symptoms at all. This fact makes PID a particularly insidious process which can cause long term fertility or health problems without giving any warning.

Prevention of PID is essential to avoid these unfortunate consequences. For women who use other reliable birth control and who therefore need not rely on condoms for contraceptive purposes, it is important to guard against sexually transmitted diseases.

For them, condom use is still required and should be used preferably in combination with a spermicide containing the ingredient nonoxynol-9. Condoms plus spermicide are the best protection from sexually transmitted infections which can lead to PID. Of course the only total protection from sexually transmitted disease is abstinence. However, a mutually monogamous sexual relationship with a partner who is free of disease makes the risk of having PID extremely small. Rarely, PID can result after pelvic surgery, abortion, IUD insertion or childbirth.

If you suspect you have a sexually transmitted disease or pelvic infection you should seek immediate medical care. If you are diagnosed with PID it is essential to completely follow your doctor's instructions. Treatment may include hospitalisation, one to two weeks of antibiotics, treatment of your sexual partner(s) and abstinence from sexual activity until all parties are curd of infection. The disease can reoccur if medication is stopped prematurely so it is mandatory that you take prescribed medication as directed and not stop simply because you feel better.

Repeat infections are common because sexual partners do not receive adequate treatment and can subsequently re-infect their partners.

PID can be a quiet disease or it can cause immediate serious illness. Its long term fertility and health consequences are unrelated to the severity of symptoms a woman experiences. The most essential fact to remember about PID, however, is that you can prevent it.

Cheryl Peek-Ball, M.D. Maternal Health & Family Planning -- Department of Health.

HEALTH AND SOCIAL ISSUES HTH