Pre-Implantation Genetic Diagnosis

in a laboratory setting -- an egg with sperm outside of a woman's womb. Once the embryo develops, it is implanted in a woman's uterus.

The majority of the process of keeping an embryo alive for an extended period of time is the same as in-vitro fertilization. “One day after retrieval (Day 1), the embryologist begins their day with the assessment of fertilization and by separating out the normally fertilized eggs. Cell division or cleavage will occur after the intermingling of the chromosomes overnight. By Day 2, normally dividing embryos should have four cells. Embryos will be further assessed on Days 2 and 3 for transfer or placement into more advanced blastocyst growth media until day 5 or 6”(AZFertility). However, in order to continue the growth, once the embryos are placed into the culture, they are placed into incubator. The majority of the difficulty is keeping the embryo alive within the

PGD is performed with IVF and followed by genetic screening for mutant gene. IVF stage, eggs are collected and fertilized by sperm in the laboratory to produce Zygotes. Then, these Zygotes carry on to growing in the laboratory for 3 days until reached eight cells stage. Biopsy of embryo is performed and extracted blastomere from each 6-8 cell stage embryo. Then, cell undergoes genetic screening for mutant gene. Un-carrier and unaffected embryos are transferred into mother’s uterus with confident no CF mutant gene for ensuring a quality of life for baby (Destouni, 2016).

into an early stage embryo while still in a test tube. Scientists place the early stage embryo into

This process allows the sex of the baby to be chosen, and allows scientist to see the genes before birth, reducing the risk of genetic diseases. The fertilized egg will sit in the dish for a couple days after the sperms has been injected using a very small needle. Then, using multiple embryo plantation, the egg gets implanted back into woman. Scientist and or doctors will perform ultrasounds after to see which embryos are healthy for parents to keep, an amazing process!

In Vitro Fertilization (IVF)involves giving a woman drugs to induce ovulation and then harvesting (collecting) those mature eggs through a laparoscope. The man masturbates to collect the semen. Then, the semen and ova are mixed in a dish, where fertilization may occur. Then the tiny, new embryonic human(s) are put into the cavity of the woman's uterus with the hope that they will plant and grow. Other sophisticated techniques having the same purpose, employ a diversity of approaches to producing a pregnancy.

The next technique routinely performed for prenatal diagnosis is amniocentesis. A long needle is inserted into the mother’s uterus to withdraw a sample of amniotic fluid containing cells shed by the fetus. The cells are cultured and analyzed for chromosome abnormalities. Despite the lengthy time in obtaining results because the cells need to be cultured, this method has become widely accepted as a safe and accurate way to determine genetic disorders.

The resulting embryo is then transferred to the woman's uterus (womb) to implant and develop naturally.” (Garcia, 2005)

In many cases natural conception, where the sperm from the male meets the matured female egg fails to work – the female does not get pregnant. Often after multiple failed attempts In-virto (IVF) is a viable option in order for a successful pregnancy to take place. The process of IVF involves an egg or multiple eggs from the woman’s ovaries and then fertilised by their male partners sperm in a laboratory. The fertilised egg, which should now have become a embryo is then transferred back into the woman’s womb to develop and grow. Any remaining eggs can then be frozen for future use. 1 In some cases during the process of IVF, multiple factors can lead to a couple to opt for the additional treatment of pre-implantation genetic diagnosis (PGD). PGD is the process of removing a cell from a IVF embryo to test for a specific genetic condition (passed on my either parent) due to chromosomal abnormalities (i.e. cystic fibrosis) prior to it been transferred back in to the woman’s uterus for pregnancy. The process of PGD increases the chance of producing a healthy baby from the eggs produced during IVF. 2

If eggs are not being obtained from donation, the prospective mother is given drugs with the purpose of 'controlled ovarian hyperstimulation ' - the ovaries are caused to release a larger quantity of eggs, on demand. For a period of one to two weeks, ultrasound is used to observe the development of immature egg cells. When ready for extraction, the woman is put under sedation and a needle is used to remove the eggs. After a few hours of allowing the eggs to mature, the polar body of an egg (result of uneven cell division, would eventually dissolve) can be taken for testing. However, this sample contains only the mother 's DNA. If the objective is to test the whole DNA of the potential child, or to account for the father 's contribution, the eggs are then fertilised in vitro (in the lab), and a biopsy (typically three days after fertilisation) of the embryo is then performed, using a cell produced from the cell division.

IVF is known as in vitro fertilisation. This procedure is done by removing an egg from a female, and a sperm cell from the male and combining the egg and sperm in a test tube. These two then form together and create a zygote, which then begins separating into and forming an embryo . Pre-implantation Genetic Diagnosis (PGD). It is known as the pre testing of pre-implanted embryos for genetic disorders. This operation has been put into place for couples whose offspring will potentially have a risk of inheriting a genetic disorder from the parents . PGD tests for many disorders that can affect the unborn embryo/baby. Some of the diseases that can be scanned for are recessive sex-linked disorders, dominant sex-linked disorders, and single gene disorders. The recessive sex-linked disorders can include Haemophilia, fragile –X syndrome, Spinal Muscular atrophy, and Myotonic Dystrophy. Other disorders that can be inherited are the dominant sex-linked disorders which can consist of Rhett Syndrome, incontinentia pigmenti, and pseudohypererparathyroidis. Some of the single gene disorders that can also be inherited include cystic fibrosis, Huntington’s disease, Tay-sachs, and sickle cell anaemia. It is said that in New Zealand alone there is a 1 in 4 chance of inheriting the disorder, and is most likely to occur with advanced maternal age, recurrent miscarriages and chromosome abnormalities . Some of the women that can benefit from PGD, are

These cell’s genetic material which consists of DNA or chromosomes within these cells are then tested for genetic or chromosomal abnormality, the unaffected embryos are then transferred to the woman’s uterus to implant. The techniques used to test for these abnormalities include fluorescent in situ hybridization (FISH), single- nucleotide polymorphism (SNP) and the newer approaches such as Comparative genomic hybridization (CGH) and next generation sequencing (NGS) and PCR. These techniques are constantly evolving to be more accurate and more informative. These techniques are used to test for genes that may produce specific diseases but can only check for diseases which have a genetic component.

Reproductive technology was developed in the biology and genetics of the embryo as it is now possible to test for chromosome and gene defects in the embryo, prior to implantation. This technique is called preimplantation genetic testing or preimplantation genetic diagnosis and is when one or more cells are removed from the embryo and analysed for chromosomal disorders or genetic diseases before embryo transfer. Therefore, assisted reproductive technologies (ART) not only assist in conception but can also avoid the birth of a child with a disability or hereditary disease. While new technologies continue to extend the available options for infertile couples, they also have the potential to help single women and homosexual couples to have children. Overall, these technologies have developed from when they were first introduced to now and have

Pre- implantation Genetic Diagnosis (PGD) using In Vitro fertilization is one of the many solutions for families to conceive children who cannot do so naturally. The term “In Vitro” is Latin, meaning “out of the body” ("In Vitro Fertilization (IVF)." Definition). The process begins with a woman taking fertility drugs in order to increase her egg count. The woman plays a physically and emotionally demanding role. She must take powerful hormones for ten days to produce multiple eggs. Every day during in vitro 's early phases, she must give blood to be tested, and then undergoes ultrasound testing so physicians can monitor embryonic development both chemically and visually (International Political Science Review 8.2 (1987)). Afterward, the female’s egg, and the male’s sperm is removed in multiples with the use of a small surgery by the name of follicular aspiration, and placed in a laboratory dish where it is then fertilized for about five to six days. At this point in the process, the newly fertilized embryo is examined to determine whether or not the embryo(s) show(s) any sign of genetic disease or any other flaw that could be potentially passed down from one or both parents. From there, a successfully tested embryo will be placed into the uterus of the female three to five days after, in order to develop naturally. What classifies as a successful embryo would be one that either shows no sign of carrier genes from either parent, or one that shows signs of a recessive carrier

The process of PGD occurs in six main steps. The first step requires the participant to undergo normal IVF treatment to collect and fertilise their eggs. Then the collected embryo is grown in the laboratory for two to three days until the cell have divided and the embryo consists of around eight cells. Once this stage is reached a training embryologist will remove one or two of the cells from the embryo. The fourth step involves the cells being tested. They are tested to see whether the embryo in which they removed contains the gene that causes the specific genetic condition in their family. The following step involves the embryos