Preimplantation Genetic Diagnosis (PGD)
Preimplantation Genetic Diagnosis (PGD)
Also known as Preimplantation Genetic Screening, the purpose of this process is to evaluate the chromosomal makeup of an egg/embryo. Because the majority of miscarriages are due to chromosomal abnormalities, many couples undergo Preimplantation Genetic Diagnosis in order to select embryos that are chromosomally “normal” and increase their chances of IVF success. An egg/embryo with too many or too few chromosomes will either 1) fail to implant in the uterus, 2) lead to a miscarriage, or 3) result in a chromosomal birth defect such as Down Syndrome or Turner Syndrome.
Another reason for performing PGD is for family balancing through gender selection. Because the gender chromosomes are identified during PGD, it is possible to select a “male” or “female” embryo for transfer to the uterus.
There are several methods of PGD, the most common of which is known as Fluorescence In Situ Hybridization (FISH). This method screens 8-12 pairs of chromosomes. After the egg is fertilized and progresses to the embryo stage, one or more cells are removed from each embryo to be tested. The cells are then analyzed via the FISH process and any extra or missing chromosomes are revealed (an extra or missing chromosome is referred to as Aneuploidy).
The shortcoming of FISH as a method of PGD is in the fact that it only screens 8-12 pairs of an embryo’s 23 pairs of chromosomes, so it is far from 100% accurate. Until recently, FISH was virtually the only way to screen embryos for Aneuploidy prior to IVF embryo transfer. A new method refined by Sher Institutes known as Comparative Genomic Hybridization (CGH) evaluates all 23 pairs of chromosomes for a far more comprehensive analysis. CGH is available at only a handful of clinics throughout the country, primarily SIRM offices. Extensive information on this remarkable breakthrough is available by clicking here.
Related Posts
In vitro fertilization (IVF) is a procedure first developed in 1978 in which a woman’s ovaries are stimulated with fertility drugs to produce multiple mature eggs, which are then removed from her body and are fertilized in the laboratory with her partner’s (or donor) sperm. The resulting embryos are cultured for three or five days … Read more
ICSI – which stands for Intracytoplasmic Sperm Injection – involves the direct injection of a single sperm into each egg under direct microscopic vision. The introduction of ICSI has made it possible to fertilize eggs with sperm derived from men with the severest degrees of male infertility and in the process, to achieve pregnancy rates … Read more
SIRM offers a full range of infertility diagnosis and testing as well as fertility treatment services. If you aren’t sure where to begin, and are asking “Do I need fertility treatment,” we can help you get oriented and develop a plan. Many couples assume that infertility is mostly a female problem. In reality, it is … Read more
Egg/embryo banking offers a potential solution for older women and those with DOR who wish to minimize the relentless effect of the biological clock. The process involves undergoing several IVF stimulation/egg retrieval procedures in relatively quick succession, and then freezing/banking all viable embryos for future dispensation, rather than having them transferred to the uterus immediately. … Read more
SIRM Physicians are able to perform a full range of reproductive surgery including: Laparoscopy This ambulatory procedure (outpatient surgery) is usually performed under general anesthesia. It involves making an incision in the woman’s belly button through which a narrow telescope-like instrument is passed into the pelvic-abdominal cavity in order to permit visualization of pelvic structures. … Read more
Disorders of sperm quality range from a low count or motility to a complete absence of sperm production. Deformities of the sperm cell shape (morphology) are important because they reflect its ability to fertilize the egg. Mild abnormalities of semen parameters can be effectively treated using techniques that “wash” away the seminal fluid to improve the … Read more
In vitro fertilization (IVF) is a procedure first developed in 1978 in which a woman’s ovaries are stimulated with fertility drugs to produce multiple mature eggs, which are then removed from her body and are fertilized in the laboratory with her partner’s (or donor) sperm. The resulting embryos are cultured for three to five days, … Read more
Ask Our DoctorsA Question
