IVF - In vitro Fertilization

IVF or In vitro Fertilization is a treatment that is offered to couples with unexplained fertility, endometriosis or the female has blocked or an absence of fallopian tubes. The female will be advised by one of the medical staff when in her cycle to start medication. All treatment centres use different drug protocols, the following example is a standard long cycle.

IVF Stage 1

The first stage of IVF treatment involves taking a nasal spray or subcutaneous injection of GnRH or Gonandotrophin releasing Hormone analogue. This drug temporarily stops the normal activity of the ovary so that ovulation does not occur when the ovaries are being stimulated. It shuts down the ‘normal’ ovarian function. Some women may experience side effects from the nasal spray or injection. These can be headaches, hot flushes or mood swings. The symptoms can be similar to that of PMT. The nasal spray or injection is taken for approximately two weeks. An ultra sound scan will then be performed to ensure that the ovaries are inactive.

IVF Stage 2

Following the scan and confirmation that the nasal spray or injection has worked, the second drug will be introduced. These are administered by subcutaneous injection. These drugs are known as FSH or Follicle Stimulating Hormones. These will be administered on a daily basis and a scan will be scheduled between Day 6-Day 9 to check the response. FSH stimulates the ovaries to produce multiple follicles. The progress will be assessed by ultra sound scans. There can also be some side effects with these drugs such as tiredness, feeling bloated or breast tenderness.

IVF Stage 3

The scan will be checking the response to the FSH injections. The follicles will be counted and measured. When the follicles are a certain size approximately 18mm, this indicates that there may be a mature egg present (unfortunately not all follicles will contain eggs). At this stage, depending on the number and size of the follicles will determine when the egg collection will be scheduled. If the ovaries have responded well to the FSH injections then another injection called HCG or Human Chorionic Gonadotrophin will be scheduled to be administered. This injection helps to mature the eggs present and to release the eggs in the follicles for the egg collection. It is advised that this injection is taken approximately 36 hours prior to the scheduled procedure. Normally after this injection all other drugs are stopped.

IVF Stage 4- The Egg Collection

The egg collection or oocyte retrieval can be performed either under General Anaesthetic or sedation. It involves a vaginal probe, similar to the one that have been used in the vaginal scans, with a needle guide attached to it. The needle then, under ultra sound guidance, is passed through the vaginal wall into each ovary. The follicles are then individually drained and an embryologist checks the follicular fluid for eggs.

Once the eggs have been retrieved they will be left to rest in an incubator. Later that day they will then be mixed with a high concentration of prepared sperm. They will then be checked the next day for fertilization and the couple are informed of the fertilization rates. The embryos are checked on day 2/3 of development. If they are progressing as expected then it may be recommended to aim for a blastocyst transfer on day 5. This can increase chances of a pregnancy.

Pronucleate Egg

IVF Stage 5-Embryo Replacement

It is at the embryo transfer that the discussion of the number and quality of embryos to be replaced will take place. The embryo replacement normally takes place with no sedation. It is similar to a smear test in that a speculum is passed into the vagina. The vagina is then cleaned whilst the embryologist loads the catheter containing the embryos. A fine caterer containing the embryo/ embryos is passed through the cervix and into the uterus. The embryo's are deposited in the uterus. This is performed under ultra sound guidance. A pregnancy test should be performed 14 days after Embryo transfer.

Progesterone

Progesterone helps to maintain the thickness of the lining of the uterus to aid implantation. The lining will have been increasing as a result of the FSH injections. Progesterone will be taken in the form of intra- muscular injection or suppository prior to or commenced on the day of the embryo transfer and continued until the pregnancy test.

Cryopreservation of Embryos

Following an IVF or ICSI cycle couples may have spare embryos that are of a good quality. The unit may then offer to cryopreserve the embryos for a frozen embryo replacement cycle.

The embryos have to be of a certain quality otherwise they will not survive the freezing or thawing process. Therefore not all couples will be offered freezing at the embryo replacement cycle. Some of the criteria the embryologists will be looking for are:

• Number of cells present in the embryo
• The number of cells correlating to the development stage of the embryo
• Degree of fragmentation in the embryo
• Number of embryos available for freezing-There may be a minimum number of embryo’s that a unit will freeze

Once the embryos have been preserved then they can be stored by the unit until a couple are ready to proceed with another treatment cycle.