9. Thorough assessment of IVF cycle
Assessing the success rate in any clinic is one of the most difficult things for prospective patients to judge. Success rate can be expressed by the number of pregnancies achieved.
There are a number of factors which affect success rates of IVF. These include:
1. Patient age. The age of the woman is one of the most
important factors in determining the chance of success. Once
over the age of 40 years, the chance of success is severely
reduced. Not only are there far fewer pregnancies per treatment
cycle, but there is also a greater risk of miscarriage. By the
age of 45, success is genuinely rare, and our oldest patient
who conceived with her own eggs was 47. It is possible to get
around many of the problems associated with age by using donated
eggs from a younger woman. However, most patients naturelly
do not want to consider getting pregnant with another person's
genetic child. Moreover, egg donors are still extremely difficult
to recruit, and there simply are not enough donors around to
offer eggs to the great majority of women who request this particular
2. Cause of infertility. Patients who have had significant
disease or scarring of the uterus, patients with certain kinds
of tubal damage and ovarian damage, patients with very abnormally
functioning ovaries and men with very poor sperm, may all expect
to have less good chance of success. During your visit to the
clinic at IVF these factors will be assessed.
3. Ovarian responce. It is quite common for some women
to consistenly produce fewer eggs, or eggs of less good quality
when the ovaries are stimulated, for example during IVF treatments.
The evidence which is available suggests that women who are
so-called "poor-responders" may also tend to ovulate "poorly"
in unstimulated cycles, perhaps when trying to get pregnant
naturally. Research certainly tends to confirm that "poor" eggs
are quite common in all women, but occur more frequently in
some infertile patients. The abnormalities include changes in
the chromosomes which carry the genetic messages, changes in
the microscopic structure of the egg itself, and changes to
its outer coat, the zona pellucida. The reasons for changes
are puzzling but it is clear that, at the present time, the
chance of a woman who is a poor responder getting pregnant is
much less than normal. Poor responce is often associated with
repeated IVF attempts; that is to say, in some women each attempt
to stimulate the ovaries results in fewer and fewer eggs being
produced. For this reason, and because an increasingly poor
response is difficult to predict, we feel it is quite important
to get the first attempts at IVF done in a clinic where there
is the best chance of success.
4. Overweight. One important factor which is far too frequently overlooked is being overweight. We now have definite evidence that being overweight can make IVF treatment far less likely to succed. Women who are overweight cut their chances by as much as half by not attempting first to lose excess fat by careful, strict dieting. It is remarkable how much better the ovaries may respond to stimulation if there is first a realistic attempt to use effective dieting. Moreover, being fat does not only reduce success rate, but it also make the treatment more risky and complications such as hyperstimulation a little more likely.
5. Sperm quality. Just as eggs can be abnormal, so can sperm. In fact, all human males produce some sperm which are totally abnormal and which have no chance of fertilisation. Even though such sperm may be capable of moving, they are unable to produce a normal embryo capable of surviving to a full pregnancy. With present scientific evidence it seems that abnormal sperm is the result of a variety of reasons in which the generic factor seems to be of primary importance. At the current time the fact is that routine IVF is frequently not successful in such cases but microinjection of sperm does offer real hope to many men with very poor sperm production.
|Spermatozoa reacting to HOST
6. Scarring around the tubes and ovaries. Some women seem to respond poorly to the run-up to egg collection because their ovaries are very scarred or cystic. Often, giving the drugs which are needed to persuade the ovaries to yield several eggs, encourages more cysts to form. Occasionally, cysts caused by endometriosis can also adversely affect the treatment. Equally, some forms of tubal disease seem to reduce the chance of success. For example, a very swollen tube filled with fluid (so-called "hydrosalpinx") may reduce the chance of pregnancy because the fluid in the tube interferes with the growing embryo after it is placed in the uterus.
7. Uterine scarring. A number of infertile women have scarring of the uterine muscle or its lining, the endometrium. Such damage can occur following severe inflammation or infection - for example, after tuberculosis. Alternatively, the uterine muscle can become involved with endometriosis. Endometriosis of the uterine muscle is called adenomyosis and is caused by endometrial tissue actually growing into the uterine muscle wall. Other conditions which can reduce the chance of success at IVF include fibroids, and adhesions or polyps in the uterine cavity. Many of these conditions can be improved before IVF and good units check on their presence before starting any IVF treatment.
8. Transfer of more than one embryo simultaneously. When a single embryo is transferred, up to 20% of women get pregnant. When two or three embryos are transferred, up to 45% get pregnant. Before any embryo transfer is done all aspects will be carefully discussed with you.
9. The ability to collect eggs around the clock, seven days a week. Although this is a strain on the staff and requires special efforts from everybody, the ability to collect eggs night or day, Bank Holidays included, has advantage for our patients. The more "ripe" the eggs, the better the success rate. Our enthusiasic team of scientists, clinicians, nursing and auxilliary staff ensures that our patients have their procedures performed exactly when needed and not only within the strict opening hours of a private clinic.
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