Medically Assisted Reproduction

IUI

This abbreviation stands for intra-uterine insemination. This means that the man’s semen is prepared in the laboratory, after which it is injected directly into the uterine cavity. This has two advantages: the sperm no longer have to get past the plug of mucus in the neck of the womb and the sperm in the prepared sample are already a selection of the best sperm. The most important prerequisite for being able to use this technique is free passage through the fallopian tubes. If they are closed, it is impossible for the sperm to reach the ovum. The stimulation treatment given with this technique is quite gentle. The goal of the stimulation is to obtain 1 to 3 mature follicles (with egg cells). With more egg cells the risk of multiple pregnancy would be unacceptably high.

IVF

This abbreviation stands for in vitro fertilisation. After the follicles have been strongly stimulated follicle puncture is performed (to collect mature egg cells from the ovary). The ova obtained are mixed in the laboratory in a dish with prepared sperm (insemination) and then placed in an incubator. The incubator keeps the culture fluid at the right temperature and degree of acidity.

As this technique places the best sperm in the immediate vicinity of the ova, it is usually not long before a sperm has penetrated the membrane of an ovum and fertilised it. If all goes well a large proportion of the eggs cells will be fertilised. If absolutely none or very few of the ova obtained are fertilised, this could indicate a problem with the ova, the sperm, or both. This is always disappointing news, but the information can be used to try another, more complicated, technique in the following cycle. After the fertilisation the embryos are regularly checked to see if the development of the embryo is normal.

follicle puncture

Usually on the second or third day following the puncture one or two embryos are placed back in the uterine cavity. This is called embryo transfer. It is a simple and painless procedure whereby a catheter (small tube) is inserted through the cervix to the uterine cavity so that the embryos and a small quantity of culture fluid can be transferred here (see Figure 6). In the uterine cavity the embryos continue to develop further until they are big enough to break through the egg membrane and implant themselves in the endometrium. Embryos that are not returned to the uterus and show no signs of serious disturbance in their development are frozen. The frozen embryos can later be thawed and placed in the uterus.

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GIFT

This abbreviation stands for gamete intra-fallopian transfer. At first this treatment proceeds in the same way as in vitro fertilisation. After the egg cells have been aspirated (sucked up) the second step follows whereby a laparoscopy is performed to place ova and sperm in the fallopian tubes. So in GIFT fertilisation does not take place in the laboratory but in the fallopian tubes. This distinction can be important for a number of reasons. For people with certain religious convictions this is a more acceptable solution than IVF, where fertilisation takes place in the lab. This technique is more invasive than IVF, does not offer any additional advantages and is not used as often at the moment.

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Special Techniques

ICSI

This abbreviation stands for intracytoplasmic sperm injection. If there are serious abnormalities in the sperm picture IVF can often not offer a solution. Although a sample is prepared for IVF using only the best sperm, in some men even the best of these is not good enough to penetrate the egg membrane “under its own steam”. If only a very low number of egg cells was fertilised in a previous attempt at IVF, there is little point in continuing. In these cases ICSI can sometimes be the way forward.

The principle of ICSI is to inject a single sperm directly into each ovum using a very powerful microscope and an ultra-fine glass needle. After the sperm has been injected the genetic material has to be released into the nucleus of the ovum and pair with that of the ovum. If that does not happen, the fertilisation is incomplete. In other words, injecting the sperm is the first step in the (in this case assisted) fertilisation, but it is only complete if the hereditary material of the man and woman fuses. That is a condition for the normal development of the embryo. So injecting the sperm into the egg is no guarantee that embryos will be obtained.

sperm injection with fine needle

After the sperm has been injected the rest proceeds as for IVF: two or three days after the ova are obtained the best embryos are replaced in the woman’s body.

MESA, TESA en TESE

In some men it can be difficult to extract sufficient good sperm from a typical ejaculation for the ICSI procedure. If this is the case, there exists the possibility of obtaining sufficient sperms directly from the epididymis (a structure associated with the testis) or the testis (testicle). It is frequently possible to obtain sufficient sperm from the epididymis or testis under local anaesthetic using a very fine needle. These procedures are known as MESA and TESA respectively and from there an ICSI procedure can be performed. In a very small number of cases aspiration using a needle is insufficient and a small incision must be made in the testis (TESE) in order to remove a small amount of tissue. The embryologist can then extract the sperm from this tissue.

Assisted hatching

The term “assisted hatching” refers to a technique by which the embryo is given a helping hand to break through the egg membrane. In some women the egg cells are enclosed by an unusually thick or hard membrane, so it is not inconceivable that the infertility is being partly caused by this. With the special microscope that is also used for ICSI a small opening is made very carefully in the egg cell membrane so the embryo can attach itself at this point. The value of this technique has been strongly criticised by many doctors however.

Pre-implantation screening

In this embryos are examined for possible genetic defects. We know that there is a direct connection between the number of genetically abnormal ova and the woman’s age. If such ova do become fertilised these embryos would not usually implant or might result in a miscarriage.

Techniques have recently been developed that make it possible to detect these genetically abnormal embryos before the fertilised eggs are replaced in the woman’s body. In other words the test can be performed on embryos that are created by IVF or ICSI. In this test a single cell is removed from the embryo for further examination. This does not threaten the continued normal development of the embryo. It enables us to only insert genetically normal embryos, resulting in an increased likelihood that the pregnancy will develop normally.

cell is taken out of the embryo

The same method is used in couples who are known to have an increased risk of known hereditary defects. Until recently there were only two ways of preventing a known hereditary disease or condition being transferred: advise the couple not to have any children or perform an abortion at the start of the second term of pregnancy if amniocentesis or chorionic villus sampling indicates that the disease has indeed been passed to the child. If the embryos are examined before they are returned to the woman, only those that have not inherited a disease can be used. This technique enables couples to have their own children safely without having to wait a long time for the result of the amniocentesis or chorionic villus sampling tests. Furthermore a second-term abortion is always a very traumatic experience form both a physical and emotional point of view. It is obvious that when testing for hereditary diseases these techniques are only possible due to close co-operation with a centre for genetic diagnosis.

Read more about Oocyte and Embryo Byopsy

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