IVF TreatmentIn vitro fertilisation (IVF) can be of benefit to many couples. In IVF, eggs are gathered from the woman’s ovaries and mixed with the man’s sperm outside the body, usually in a glass dish in a laboratory. ‘In vitro’ comes from the Latin and literally means ‘in glass’, a reference to the glass container where fertilisation takes place. (While this is usually a dish, the term ‘test-tube’ babies has become widely used.) The fertilised eggs are then cultivated to embryo stage and transferred to the woman’s uterus. Couples may be offered IVF if:
While the procedure described above sounds simple, in reality IVF is a complex and emotionally demanding process. It can take between six weeks and two months on average for a single treatment cycle and most couples find it both physically and mentally stressful. The first stage involves stimulating the woman’s ovaries so that several eggs mature. Normally, a woman produces one egg in each menstrual cycle, but because the chances of getting pregnant through IVF are much higher if more than one embryo is replaced, the aim is to cultivate several eggs. To achieve this, a woman will need to take drugs to suppress her own hormones. This phase lasts about 21 days. The drugs have the effect of putting the body into a temporary menopause, along with all the side effects that might be expected, such as hot flushes and mood swings. Once the woman’s own hormones have been suppressed, she can begin taking the drugs that will stimulate egg production. She may need to have injections daily for around 12 days, but this will vary according to the way her body is responding. The response of the ovaries will be carefully monitored using ultrasound scanning to show the size and number of developing follicles. Monitoring is essential because sometimes a woman’s ovaries respond very strongly to these drugs and begin to swell. This may result in ovarian hyperstimulation syndrome, which can cause a range of symptoms from mild abdominal pain to severe pain, vomiting, nausea and dehydration. Sometimes (in around 18 per cent of cases) a treatment cycle has to be abandoned at this stage, either because of hyperstimulation or because not enough follicles are produced or they grow very poorly. If all goes well, however, the next stage of the procedure is egg collection. This takes place when the ultrasound scan shows a sufficient number of large follicles. The woman is given an injection late at night to give the eggs their last ‘push’ towards maturity. Ovulation normally occurs 37-40 hours after this injection, so egg collection is scheduled to take place just before ovulation occurs. The eggs are usually collected using a fine, hollow needle guided by ultrasound. Around the same time, the man needs to produce his semen sample. The semen is assessed and if it’s of sufficient quality, it is ‘washed’ to separate the best quality sperm in preparation for fertilisation. As soon as they’re extracted, the eggs are put into a nutrient medium with the sperm and then cultured in an incubator. The next day, they’ll be observed through a microscope to see if fertilisation has occurred. If it has, 24 hours later cell division will have started and the embryo might now have two or four cells. The embryos will be checked by an embryologist to make sure that they’re developing normally and, if all is well, embryo transfer can take place. The embryos, together with a tiny amount of nutrient fluid, are put into a catheter and placed into the woman’s uterus through her cervix. No more than three embryos can be transferred, by law, to reduce the risk of a multiple pregnancy. If there are ‘spare’ embryos of good quality these can be frozen and stored for use in a future treatment cycle. Transfer is usually quick; some women find it painless, others more uncomfortable - rather like having a cervical smear test. Afterwards, the woman will be advised to rest for a short time and then go home and ‘carry on as normal’. It will be about two weeks before a pregnancy test can be done, and this waiting is one of the most difficult and stressful times of the whole procedure. During this time, the woman will be prescribed progesterone, either in the form of pessaries or injections, which is needed to provide hormonal support to any potential pregnancy. If the pregnancy test is positive, an ultrasound scan a couple of weeks later will confirm this. It also allows clinic staff to check that the pregnancy has implanted well in the uterus and to count the number of gestational sacs. If all is developing normally, the woman will be referred back to her GP and make the transition to antenatal care. However, one of the most important things to remember about IVF is that, statistically, it is much more likely to fail than it is to be successful. Unfortunately, the impression given by some TV programmes and magazine articles is that most couples will emerge from the process of IVF with their longed-for baby, but in reality a success rate of around 22 per cent is the national average and you may be more or less successful depending on your own particular circumstances. This ‘failure’ can be a crushing blow for couples, who then have to decide whether to embark upon another treatment cycle with the hope that they will be successful next time. In such situations, the counselling offered by the clinic and the support from groups such as Issue and Child can be invaluable. FETWith IVF, only embryos that divide (cleave) will be transferred into the patient's uterus. If more than the appropriate number of embryos needed for transfer are obtained, they may be frozen and used at a later date. Replacing fewer fresh embryos decreases the multiple birth rate and increases the success rate per stimulated cycle. It may also enable the patient to have more than one frozen-thaw cycle before needing to face the extra expense of another stimulated cycle. However, frozen embryo transer isn't without its problems as many embryos don't survive the freeze-thaw cycle and some clinics are better than others at defrosting and replacing frozen eggs. With IVF, 'assisted zona hatching' may also be offered, especially to couples where the woman is 38 years old or more, or for frozen embryo replacements. The technique involves using a laser to create a small hole in the zona pellucida of the developing embryo to help it to break out of its shell and implant more easily in the wall of the uterus.
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