Hormone Assessment of the Female
The first step in the investigation of a woman's fertility is to establish whether or not she ovulates (produces an egg) every month. This can normally be confirmed by performing blood and urine tests to measure the level of hormones at specific stages of the woman's cycle. The hormones responsible for the development of eggs within the ovary include Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH),while Progesterone and Oestrogen are produced during this time by the ovary. The levels of these hormones will rise and fall depending on the stage of the woman's cycle.
If conception is to occur easily and naturally it is essential for a woman to have patent (open) and undamaged Fallopian tubes in order for the sperm and egg to meet In order to check the patency of the Fallopian tubes as well as the condition of the uterus and ovaries, a Laparoscopy can be performed. This procedure involves inserting a small telescope known as a laparoscope through the abdominal wall when the pelvic organs can be clearly seen. A laparoscopy is performed in the operating theatre, usually as a day-case under a general anaesthetic.
A hysterosalpingogram may also be used to check whether or not the Fallopian tubes are blocked. This is an x-ray procedure involving the injection of a special dye through the cervix and into the uterus. The passage of the dye through the Fallopian tubes can be observed on the x-ray. If the dye fails to spill out through the end of the tubes, this indicates that they are blocked or that a spasm has occurred and needs further investigation. (Laparoscopy and dye test).
Post Coital test
A post coital test can be performed. collecting mucus from the cervix at the time of ovulation about eight hours after sexual intercourse has taken place and viewing it from a microscope to assess wether there are any sperm present and there movement. The presence of antisperm antibodies within the mucus may be indicated by sperm demonstrating a shaking movement.
A small telescope connected to a camera is inserted through the cervical canal. This is done either under general anaesthetic or under sedation as a day case. The uterine cavity will therefore be seen and examined under direct vision. Pathology best seen with this technique includes sub-mucous fibroids, ie fibroids developed within the uterine cavity, endometrial polyps or adhesions.
Based on the the principle of sonar, ultrasound scan is a non invasive technique allowing internal organs to be seen on a screen. A small probe is inserted in the vagina so the uterus and both ovaries can be seen. Ultasound scan is a major tool to monitor ovarian stimulation during IVF, to check patients for fibroids or ovarian cysts and also to monitor pregnancy.
Screen for Cystic Fibrosis
Cystic Fibrosis is the commonest genetic disease amongst caucasians, 1 in 25 persons being carriers of this defectivegene but being otherwise normal. However the incidence of Cystic Fibrosis is a lot higher in men having congenital bilateral absence of vas deferens thus justifying a systematic screening.
INTRA-UTERINE INSEMINATION (IUI)
IN VITRO FERTILISATION (IVF)
IVF is a technique involving the fertilisation of eggs by sperm outside the body. The term literally means 'fertilization in glass' - hence the commonly used description 'test-tube baby' technique.
When is IVF Appropriate?
IVF was developed as a treatment for women who have blocked or badly damaged Fallopian tubes which prevent the egg and sperm from meeting. However, it may also be used in some cases where a woman has endometriosis, the male partner has poor quality sperm or where the cause of infertility is unknown.
What does treatment involve?
- IVF treatment is made up of a number of procedures usually referred to as a 'treatment cycle'. An outline of what is involved in a typical IVF treatment is described below.Down regulation - Firstly, the woman is prescribed a drug taken in the form of a nasal spray or an injection which suppresses the release of the hormones responsible for the production of an egg. This is necessary in order to establish a 'baseline' from which to start ovarian stimulation and to prevent spontaneous ovulation before egg collection can take place.
- Ovarian stimulation - Once a base line has been established, the woman commences ovarian stimulation which takes the form of a daily intra-muscular injection. Stimulating the ovaries in this way should produce several eggs to ensure that there are enough suitable eggs for fertilization.
- Monitoring - Regular monitoring of the effects of the drugs on the ovaries is undertaken through ultrasound scans and blood tests.
- Final injection - When the ultrasound scan and blood tests indicate that there are a sufficient number of mature follicles (the sacs in which the eggs grow), a final injection is administered to ensure the ripening of the eggs in preparation for the egg collection.
- Egg collection - Eggs are collected from the ovaries through the vagina using a fine needle under ultrasound guidance to aspirate the eggs from the follicles. This is performed as a day-case in tour Day Care Unit, typically under sedation.
- Sperm production & preparation - On the day of the egg collection, the male partner is required to produce a semen sample at the centre. The sample is then prepared in the laboratory to extract the most motile sperm.
- Embryology - When all the eggs have been collected, they are put in a dish with the prepared sperm and incubated in the laboratory. Approximately sixteen hours later, the embryologist will check to see whether fertilization has occurred.
- Embryo transfer - If fertilisation has occurred, usually two of the embryos are transferred directly into the uterus two days after the egg collection. The embryos are transfer through the vagina and cervix using a fine catheter. This procedure is usually pain free.
- Pregnancy test - A pregnancy test should be carried out fourteen days after the embryo transfer. If the result is positive, an ultrasound scan is recommended two or three weeks later to check the embryo is alive and situated in the uterus.
What causes IVF to fail?
During an IVF treatment cycle, a number of problems may arise which cause the treatment to be cancelled or to fail. These include the following:
- In the lattercase, our policy to continue with down regulation but with hold the estumulating injection until it is safe to do the egg collection without risk of ovarian hyperstimulation.
- The ovaries may either fail to respond to the stimulating drugs or over-respond. In the former case the egg collection would not go ahead.
- Very rarely, although ultrasound scans indicated the presence of follicles, no eggs will be found during the egg collection procedure.
- The collected eggs may fail to fertilise in the laboratory and therefore no embryos would be available for transfer.
- The eggs may fail to divide after fertilisation and therefore cannot be replaced into the uterus.
- After the embryo transfer, the embryos may fail in implant in the uterus. This is the most common reason for an IVF treatment to not result in pregnancy.
Freezing and storage of embryos
In cases where more than three embryos result from an IVF treatment, it is sometimes possible to freeze and store these embryos for five years in the first instance. This enables women to have a further treatment without the need for ovarian stimulation or egg collection.
In order to prepare the uterus to receive embryos, a course of drugs is administered to thicken the endometrium (the lining of the uterus). Embryos are then thawed and replaced directly into the uterus. However, some embryos may deteriorate during the thawing process and would therefore not be replaced. The pregnancy rates for frozen embryo transfers (FETs) are generally lower than those using fresh embryos.
INTRA-CYTOPLASMIC SPERM INJECTION (ICSI)
The microsurgical fertilisation technique of ICSI is currently the most advanced technique available for the treatment of male infertility. It is used in conjunction with IVF and involves an extremely precise microscopic surgical procedure on an egg to assist fertilisation.
When should ICSI be used?
ICSI can be used in cases where the man produced only a very small number of sperm which are incapable of penetrating the barriers surrounding the egg unassisted. This is usually because the sperm have extremely poor movement or no movement at all. ICSI is also mandatory when sperm is directly retrieved from the testes.
What does the treatment involve?
Eggs and sperm are collected in the same way as in a normal IVF treatment. However, unlike conventional IVF a single sperm is picked up from a prepared sperm sample in a very fine glass needle and injected through the zona pellucida and the egg membrane directly into the centre of the egg. In this way, the sperm is not required to penetrate any of the surrounding barriers. The injected eggs are then incubated for sixteen hours and checked to see if fertilization has occurred. If fertilization does occur, up to three embryos are replaced two days after the egg collection as in a normal IVF treatment.
Testicular Sperm Extraction (TESE/TESA)
Total azoospermia (total absence of sperm in the ejaculate) can be due either to a blockage, absence of the vas deferens or to a failure of the testes to produce spermatozoa. The degree of this failure can be variable.
In cases of testicular failure, it is now possible in around 50% of cases to collect at least a few sperm by performing one or multiple testicular biopsies. Provided some motile sperm are recovered, the chance of fertilization of the egg is again extremely good.
Testicular Biopsy involves taking one or several small samples of the testes - either for analysis, or for the recovery of sperm in the most severe cases of azoospermia. These operations are done as day cases under general or local anaesthesia with or without intravenous sedation.