Use Of The Embryos example essay topic

Prenatal ultrasound 1. Explanation Ultrasound examinations are used by doctors in order to get an impression of the progressing development of the unborn child. With the help of this process corporal deformities, state of the organs, amount of amniotic fluid and the growth of the child can be seen. Most misshapen body parts can be recognized by using ultrasound. The process also tells the doctor in which week the pregnancy is or how many fetuses there are.

After an ultrasound examination the following information can be given: limb length, diameter of the amniotic fluid sac, diameter of the fetus' head and stomach. Those numbers are measured in order to estimate whether the child's development is normal. Ultrasound works with silent sound waves with are reflected by the body tissue. The sound waves are reflected there where the density of the tissue changes, e.g. amniotic fluid, umbilical cord.

The ultrasound images are like cross-sections of the body but it's quite hard at the beginning to recognize something on them. Apart from the normal ultrasound images there are two other techniques which aren't used in most pregnancies. They are called echocardiography and vaginal ultrasound. The echocardiography measures the child's blood flow to discover an insufficient supply. The vaginal ultrasound has become more and more used in the recent years.

In this technique the ultrasound doesn't go through the stomach but through the vagina. It is used to discover pregnancies in the fallopian tubes or other irregularities. 2. Diagram 3. Ethical problems Today ultrasound is assumed to be harmless to both, mother and child.

It is commonly used during most pregnancies from four weeks gestation. As ultrasound isn't fist of all used to decide on abortion and not useable to detect genetic abnormalities it is not nearly as much criticized as PGD, amniocentesis or CVS. Ultrasound has the advantages that it's not a complicated process which doesn't take up a lot of time. Apart from that it's good that it isn't expensive and can be done right on the spot. A problem is that the measurements and information might not be exact and could confuse the parents.

4. Bibliography web Student Resource Manual Amniocentesis 1. Explanation This technique is performed 14-16 weeks into the pregnancy. The amniotic fluid which contains some fetal cells is taken from the amniotic sac by using a hypodermic needle which is inserted into the woman's abdomen. This is guided by ultrasound. In the process about 30-60 ml of amniotic fluid are taken from the amniotic sac.

After that the amniotic fluid is centrifuged in order to separate the fluid from the fetal cells. Then the cells are cultured and after three weeks biochemical tested and chromosomal analyzed such as karyotype d where the chromosomes are counted and displayed. The amniocentesis is used when the pregnant woman is approaching 40 years because the risk of down-syndrome is increased, when the parents are carriers of genetic disorders or already have a child with a chromosomal disorder. The process contains a risk because it might cause spontaneous abortion or might damage fetus or placenta which can lead to a miscarriage. For women younger than 35 years the risk of causing of miscarriage is higher than the actual probability of the child having chromosomal abnormalities. 2.

Diagram 3. Ethical problems After amniocentesis is performed and chromosomal disorders such as down-syndrome and cystic fibrosis might have been discovered these results are often used to decide on abortion. The parents are confronted with the decision of wanting to live with an abnormal child. As the woman is already at over three months into pregnancy the woman's condition is already visible. Her environment might try to influence her decision and she might have to justify the termination. The abortion process provides mental stress for the woman because she has to deliver the baby in a process similar to a normal birth.

The other fact influencing the mother is that the baby has the right to life although it is disabled. The child is challenged with a handicap but is still a precious human being who needs the mother's love and care more than ever. Various religions see abortion as an act of murder which is against God's will. 4. Bibliography Student Resource Manual Microsoft Encarta Encyclopedia web web Prenatal Genetic Diagnosis (PGD) 1. Explanation Pre implantation genetic diagnosis is performed on early embryos before implantation and pregnancy.

This genetic test gives information about the embryos' genes and inherited diseases or chromosomal disorders can be discovered in a single cell. The information gained by this technique is used to decide which embryo should be implanted in the mother's uterus. PGD takes place after an in vitro fertilisation where several embryos are fertilised. The embryos' genetic material will not be altered when the PGD is used. The early embryological development is still similar to the natural way. The embryos which develop normally are biopsied on the third day after the fertilization under microscopic observation.

Very fine glass needles and tools are used. A sufficient amount of cells (from the blastocysts) has to be obtained. The removal of these cells has proven to have no effect on the further development of the fetus. The removed cells from each embryo will be analysed genetically.

The tests used are Polymerase Chain Reaction (PCR) or fluorescent in situ hybridization (FISH). The PCR is performed to detect single genetic disorders. The FISH-technique is used for chromosomal analysis to test for sex-linked (x-linked) disease and chromosomal abnormalities. 2. Diagram 3. Ethical problems In PGD only completely healthy embryos are transferred into the uterus.

This method is seen as an early stage of genetic engineering on humans. It is predicted that as soon as the DNA is decoded completely all the embryo's features will be determined and only babies with the desired look, character and intelligence will be born. PGD is criticized because it might lead to a society where only perfect babies can be born. PGD has the ability to create a greater race and supports eugenics. PGD has to be used after any assisted reproduction technology (ART) treatment and therefore performing ART with the ethical issues involved leads to ethical problems arising in PGD. Another question is at what point or number of cell divisions embryos take on the aspects of personhood and therefore if they should be used for research purposes.

4. Bibliography web web web web Chorionic villus sampling (CVS) 1. Explanation In the CVS a sample of the chorionic villi is taken from the tissue which will develop into the placenta by using a thin tube which is inserted either trans abdominally or transcervically depending on the location of the placenta. This process is ultrasound guided and 10-15 mg of the tissue are obtained. This tissue is manually cleaned of maternal uterine tissue and then grown in culture, and a karyotype is made like in amniocentesis. CVS is done at 8-10 weeks into the pregnancy.

The amount of fetal cells in the chorionic villi is greater than in the amniotic fluid and the cells don't have to be cultured therefore the results of the chromosomal testing can be obtained earlier. CVS is an alternative to amniocentesis however the risk of miscarriage is higher and the results might not be as accurate. 2. Diagram 3. Ethical problems CVS is done to decide on termination because of genetic abnormalities therefore it is condemned for killing human beings because they don't fulfill the society's expectations. If a termination is done due CVS results the process is easier for the woman because the pregnancy is at an early stage.

The termination method can be performed before the woman's environment is conscious of the woman's condition. It is less stressful for the pregnant female because she is under anesthetic while the termination is made. The ethical background behind CVS is roughly the same as behind amniocentesis. The usual questions which go with abortion appear. Prenatal testing methods such as CVS, ultrasound, PGD and amniocentesis may all indicate genetic disorders however they cannot determine the severity of the problem. Many persons with disorders such as spina bifida, down-syndrome or cystic fibrosis still lead rich lives and are only mildly affected, though other disorders turn out to be more severe.

4. Bibliography Student Resource Manual web web web IVF (In vitro fertilisation) 1. Explanation In an in vitro fertilization one or several eggs are fertilized outside the female's body. The woman is given hormonal medication in order to stimulate the growth of several eggs. There are two different techniques to gather the eggs. In most cases a needle is inserted through the cervix and the eggs are recovered with the help of ultrasound guidance.

The other method is called laparoscopy where the eggs are obtained through a small incision in the abdomen using a laparoscope for guidance which is inserted through the navel of the woman. After that the eggs are placed in a special fluid. The sperm that has been collected is washed and incubated and the introduced to the eggs and left for approximately 18 hours hoping for fertilization. Then the eggs are removed and out into a special growth solution.

They are examined about 40 hours later for abnormalities. If the fertilization were successful it's common to transfer several embryos into the uterus to increase the chance of pregnancy. There is a 20% chance with every IVF cycle. If more than four embryos have been fertilized they may frozen and used in a later embryo transfer. 2. Diagram 3.

Ethical problems As some religions only think of natural conception of the right way of fertilization IVF is criticized for acting against the nature and God's will. The IVF procedure places an enormous amount of stress on the relationship and some couples aren't able to continue due to this. It can be very depressing in the case of failure. As IVF fertilised embryos are tested by PGD for chromosomal disorders the embryos which are transferred have been selected because they have not shown abnormalities therefore PDG controversy applies. Another issue is that post-menopausal women get pregnant by IVF. The major problem is that if multiple pregnancies occur then selective reduction has to be used to limit the number of live births.

IVF is seen as the first step towards a nation of designer babies. IVF provides lesbian couples with the ability to be a biological parent. The IVF treatment is considered as unfair as it involves a huge expense which is prohibitive to many couples. 4. Bibliography Student Resource Manual web web web Sperm injection 1.

Explanation In an intra cytoplasmic sperm injection (ICSI) a single sperm is directly injected into the oocyte (egg). This method is often used when fertilization through IF has failed which means that the major block of male fertility is at the physical union of the sperm and the egg. For its maintenance and survival the human egg is protected by several barriers which may also work against normal fertilisation. If the amount of motile sperm is lower than 20 million the chance of a fertilisation is reduced, although only a single sperm is necessary. ICSI is performed to help males with low sperm numbers to become fathers.

Sperm injection is one of a group of assisted reproductive laboratory procedures referred to as micro manipulation. It is performed under very controlled environmental conditions. ICSI requires high power magnification and specialized equipment which is designed to allow the embryologist to make very small movements. The fertilization is performed with a glass tool (holding pipette) which is stabilizing the egg while a second microscopic glass tube (injection pipette) containing the sperm in used to penetrate the egg membrane.

A single sperm is injected into the oocyte's cytoplasm. An enzyme is used to aid in removing the supportive cells surrounding the egg and to better visualize the oocyte. The sperm are poised in a chemical to improve its handling with the injection pipette. After the inserting of the sperm the oocyte is released from the holding pipette and washed in a drop of a special solution.

On the morning after the ICSI the oocyte will be tested for evidence of fertilization. Fertilised eggs will develop to blastocysts in the following days before several normally developing ones are transferred to the uterus or cryo preserved. In another form of sperm injection called insemination the sperm is injected into the woman's vagina or cervix at the time of her ovulation and a normal fertilisation takes place. 2. Diagram 3. Ethical problems As ICSI is no process of natural conception a great effort has to be made to fertilised the egg.

Because of its expense the number of couples who have the possibility of using sperm injection and other techniques enhancing human fertility is limited. It is considered unwise if men who have a low sperm count pass their genes which might contain those fertility limiting factors on to their offspring. In addition natural fertilisation involves the fact that out of millions of sperms only the strongest one fertilizes the egg which has an optimizing effect on the quality of the resulting pregnancy. 4. Bibliography web Encyclopedia Britannica web web Surrogacy 1. Explanation Surrogacy is a technique to help infertile couples to get a baby which is genetically related to at least one of them.

In surrogate motherhood another female either carries her own egg which has been fertilized with the future father's sperm or the couple's fertilized egg is implanted into the surrogate mother's uterus. In this case the egg has been fertilized by in vitro fertilization and is implanted by embryo transfer. Therefore the birth giving mother is not related to the embryo. Surrogacy is used by couples where both partners are infertile but have healthy gametes, or the female doesn't have functional fallopian tubes, ovaries or uterus. It is also a possibility which may help homosexual couples to produce children who are related to one of them. Before the pregnancy, the surrogate mother enters into an agreement that she will hand the child over to the parents after having given birth.

The parents raise the child as their own but they might have to adopt it. 2. Diagram 3. Ethical problems It is said the motherhood shouldn't be a service for which someone can be paid for. It is illegal in New Zealand to advertise for surrogate mothers and only medical expenses should be covered by the payment. Part of surrogate motherhood is that the embryo will be traded with and recognized as someone's property.

Giving birth to children is created as a process where only one couple is involved. With surrogate motherhood the pregnancy is more complicated as a third party is involved. It is different from adoption in the way that it is planned before the baby's birth who other than the delivering mother will raise it. Another fact is that the biological parents then legally have to adopt their child. The surrogate mother still has the right to change her mind of handing the baby to its parents after the birth.

There is a controversy over who has the right to terminate the pregnancy if abnormalities are discovered from ultrasound scans during the pregnancy. If the baby is born disabled the biological parents might not want the child. 4. Bibliography Microsoft Encarta Encyclopedia web Embryo freezing 1. Explanation Embryo freezing (cryopreservation) is used after assisted reproductive technologies (AFT) such as IVF and ICSI where more embryos are fertilized than actually needed.

If 3-4 embryos are replaced the rest will be frozen. Only embryos displaying a sufficient quality and are likely to survive cryopreservation will be stored. This allows future replacement cycles without additional egg gaining, IVF or ICSI. Normally, the embryos are stored up to five years and depending on the couple's decision discarded or donated for research purposes afterwards. Embryos stored with cryopreservation which means they are placed in liquid nitrogen tanks at -196 o C can be preserved for decades. The storing can begin in the single cell stage and the blastocyst (32-64 cells) stage of embryonic development.

A chemical solution (cryoprotectant) is used to replace water which would form ice crystals as the temperature decreases and destroy the embryos. When the freezing ends the cryoprotectant is removed and replaced with water. To transfer the embryos into the uterus, the same technique (embryo transfer) as after IVF or ICSI cycles is used. 2. Diagram 3.

Ethical problems The question of the ownership in case of the parents's separation, the usage after one parent or both parents' death (s) is even a bigger issue than in the ownership of ovarian tissue. If the mother had an embryo inserted after separation or divorce the baby would legally be the husband's child. The question is: Is he responsible for the child's financial support? Every scenario regarding ownership has to be covered in an agreement prior to the freezing of the embryos.

The major concern is the problem of what is done with the unused embryos when the family is complete. It is hard for the parents to decide on the further use of the embryos because seeing the children they already have growing up might encourage them to give their frozen embryos the "right of life". 4. Bibliography web web web Freezing ovarian tissue 1. Explanation Ovarian tissue freezing (cryopreservation) is used for women who are likely to lose their ovarian function and / or oocyte quality. This could be caused by medical conditions or therapies.

Primordial follicles which contain very immature eggs are located on the outer coating of the ovary. Ovarian tissue cryopreservation has been invented to collect and store the tissue in order to be used later as a source of healthy oocytes. As the technology is still in its development it can't be guaranteed that the eggs recover from the freezing. The oocytes are gained with laparoscopy where the laparoscope is inserted through a small incision in the abdomen. Several other instruments which are necessary for holding the ovary and gaining the ovarian tissue are also inserted through punctual incisions. Small slices of tissue are cut off the ovary and placed into a special fluid for transportation to the laboratory.

A small amount of the tissue is used to prove the presence of primordial follicles and the rest is prepared for the freezing for which it is put into a solution containing cryoprotectant. The tissue is packaged into a small labeled plastic container and frozen in a pre-programmed machine to -196 oC. It is later stored in liquid nitrogen. 2. Diagram 3. Ethical problems The women who freeze their ovarian tissue still have to pay annual fees for storage and further costs for the la boric work.

As the whole process is still in its development the law restrictions are often not sufficient. The rules about ownership of the eggs are not clear between the storage laboratories and the couples. In case of separation or death of one partner the oocytes are sometimes just forgotten. Inappropriate and misuse are the most controversial issue. There are cases known where doctors have been accused to have gained more ovarian tissue than needed and inserted it into other women without the donors consent or even knowledge. Internet pages are selling top models' eggs for high prices and newspapers offer eggs from donors with "college-level athletic ability" for $200,000.4.

Bibliography web web.