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Infertility Information |
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Causes And Management Of Infertility
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Causes And Management Of Infertility One in every 6 couples need specialist help because of infertility including those needing help though they have conceived before. But the help needed may only amount to diagnosis and advice. Infertility is seldom absolute, i.e. with zero chance of conceiving. That only occurs if both tubes are completely blocked, or if there is a premature menopause or complete lack of sperm. Most infertility is really some degree of subfertility, and the first requirements of diagnosis are accurate definition of any cause and accurate estimation of the chance of conceiving without treatment. Some disorders cannot be cured or improved by treatment. On the other hand some couples will be found to be normal with a good chance of conceiving without treatment. In many conditions the choice of treatment will depend on the relative chances of success with more or less complex methods of treatment, and compared with the chance of conceiving without help. The choice may not always be clear-cut, but the options should at least be made clear.
Ovulation failure is indicated by absent or infrequent menstrual periods (called amenorrhoea and oligomenorrhoea respectively). There are numerous distinct causes of ovulation failure, and several hormone and other investigations are required to reach an accurate diagnosis and select the right treatment. But with the exception of a premature menopause, nearly all cases can be successfully treated.
Tubal damage and pelvic adhesions (scar tissue causing the organs to stick together) are usually due to infection which can arise by sexual transmission, or after miscarriage or childbirth, or from appendicitis or abdominal surgery. Infection often causes irreversible functional damage to the lining of the tubes, which cannot work properly even if surgery is successful in opening up any blockage. In general, therefore, pregnancy rates after tubal surgery are not very good. However, if carefully chosen, a minority of cases do much better though the eventual chance of success is seldom greater than 50%. The majority would be much better having IVF treatment (in vitro fertilisation, or the "test-tube" method) to by-pass the problem. IVF involves the use of hormone drugs to stimulate multiple ovulation; tests to monitor the ovarian response and timing; an operation to collect the eggs by needling the ovaries; special preparation of the sperm to fertilise the eggs in the laboratory; and transfer of the fertilised eggs (now called embryos) through the cervix into the uterus after 2 or 3 days.
Rarely is there complete absence of sperm, due to failure of production or a blockage. The problem is mostly disordered sperm function (dysfunction), which may occur with low or normal sperm counts in semen. In a minority of cases dysfunction is due to antibodies to sperm, but in the majority the cause of dysfunction is not understood. Sperm dysfunction may cause severe subfertility, even when sperm counts in semen are normal. Then there is virtually no effective treatment to cure the dysfunction and improve natural fertility. However, IVF methods can now do much better particularly when usually the ICSI technique where a single sperm is introduced directly into an egg using an extremely fine needle. Otherwise donor insemination offers the only realistic hope of achieving a pregnancy. Semen collected from anonymous fertile donors are carefully checked for health and infection risks is freeze-stored. Physical characteristics of a donor can be matched to those of the infertile husband and the selected semen is simply injected into the cervical canal. However, such treatment obviously requires special consideration and counselling.
This means that all the key tests of fertility appear normal. It is specially frustrating because of lack of any cause to be found and lack of specific treatment. In fact much help can be given by accurate investigations in the first place, which in turn enables confident prediction of the chance of natural conception, which is often good; and where necessary, there is now effective treatment. Couples with unexplained infertility who have been trying for no more than 2-3 years have a good chance of conceiving without any help. They are clearly mostly normal and have simply been unlucky so far. All they need apart from diagnostic investigations is advice and encouragement. After more than 3 years, however, the chance of natural conception falls and offers unrealistic hope. On the other hand, fertilising ability of the eggs and sperm is mostly favourable, and IVF and related methods now offer a chance of pregnancy that is as good as normal in each cycle of treatment in the leading centres.
In this condition, tissue resembling the lining of the womb is found in other sites in the body but particularly in the pelvis. There are several systems used for classifying endometriosis: they all are centred around whether the condition is found as minor disease (wherein the disease is found scattered throughout the pelvis), or major disease (wherein the disease has caused structures within the pelvis to be stuck to each other and to lose their function). It is easy to see why major disease will affect fertility. Fallopian tubes and ovaries may be densely bound in adhesions. The situation in minor disease is more complex: indeed, many doctors do not consider that minor endometriosis is a cause of infertility. Others including ourselves have shown reductions in fertilisation rates in women with minor endometriosis in both drug-stimulated and natural cycle stimulated IVF, when compared to women with blocked tubes. Therefore, it is likely that even minor endometriosis may be detrimental to fertility. Treating the endometriosis by diathermy at laparoscopy has been shown to improve fertility.
There are many other uncommon causes of infertility, which are not possible to discuss in this basic review of infertility. However, they will also be picked up by the basic investigations that have been described, though more detailed tests may be required. Fortunately many can be treated successfully in some way.
The ideal timing is the day before ovulation, when the mucus is at its best and most receptive, so that sperm will be made already available as soon as the egg is released. The sperms are stored in the mucus and their steady release effectively bridges the gap between intercourse if no longer than 1-2 days. Therefore, so long as couples have intercourse every couple of days timing will usually be favourable. But for those who have intercourse perhaps once a week or less it would be particularly helpful to learn to recognise the pre-ovulatory mucus surge, to ensure accurate timing in every cycle. Women who cannot recognise their mucus surge, or who are unsure and would like confirmation, can check timing by daily urine testing for the LH (hormone) surge. The LH surge triggers ovulation and occurs the day before it. But LH testing is much more expensive than mucus recognition! It costs around £20 each month, depending on the number of tests needed before the LH surge appears, using test kits sold in chemist's shops. Furthermore, the ideal timing of intercourse is before the LH surge appears in the urine. See also: |
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| Bristol Centre for Reproductive
Medicine, Southmead Hospital, Bristol. BS10 5NB Phone: +44 (0)117 3232100 Fax: +44 (0)117 3232001 |
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