What is the difference between pgd and ccs

Previous versions of PGS allowed the testing of only 9 pairs. For example, studies show increased birth rates and decreased miscarriages in women over 35 who opt for these screenings. The IVF clinic extracts eggs from the ovaries after the woman goes on a course of hormones.

The clinic fertilizes the eggs with the sperm. Once the embryos reach 5 days, genetic material harvested from the embryos goes to a lab for testing. At this point, the clinic freezes the embryos. The lab will then test the sample for hundreds of known and unknown defects, including aneuploidy. With the results back to the clinic, the patient and physician review the results.

The clinic keeps and thaws the best embryo on the day of IVF implantation. The clinic also keeps the best embryos for future IVF cycles if necessary. This reduces the chance of multiple births and miscarriages. Patients should keep this timeframe in mind. Couples should consult with a fertility specialist to find out the best genetic screening available.

The tests require very skilled medical practitioners and labs. As the process constantly changes, clinics must stay ahead of the curve to provide patients with the best genetic screening. Also, patients with repeated IVF treatment or recurrent implantation failures can consider it.

Sometimes, IVF treatment may fail because of a genetical abnormality in the transferred embryo. Without doing genetic testing of the embryo or embryos , there is no way of knowing for sure it is genetically normal or not.

This is the case even if the embryo developed well and looked healthy on the day of embryo transfer. Other patients such as those with recurrent pregnancy loss or repeated miscarriages can also think of having PGS or CCS. Almost one percent of women of reproductive age may experience repeated miscarriages. This is defined as loss of three or more pregnancies.

Almost sixty percent of these early miscarriages before twelve weeks of pregnancy are due to genetically abnormal embryos. Hence, testing the embryos and replacing them with genetically normal embryos is necessary.

It may improve the chances of such couples having a successful ongoing pregnancy and childbirth. Some patients with male factor infertility may also consider it. When the cells are dividing, the genetic material should split equally between the two resultant cells. But, sometimes this might not be the case. Some cells may have a higher number of chromosomes and the other may have fewer than desired. Also, it does not test for the genetic codes that are responsible for expressing different traits in the child.

So, even if the tested cells have a normal chromosome number or amount of genetic material, the embryos may still carry an abnormal gene or genetic code. CCS allows us to determine, at the embryo stage, how many chromosomes are present and therefore whether the embryo has the potential to make a live birth. CCS allows us to assess the chromosomes of an embryo and therefore serves as a screening tool. For example there are lethal diseases, such as Tay Sachs Syndrome, which are recessive gene diseases.

This means that the parents were carriers of the abnormal gene, but since they had a normal gene on the other chromosome, they do not have the disease. If two carriers reproduce, one quarter of the offspring will inherit the abnormal gene from each parent and therefore will have the actual disease.

PGD allows us to determine whether a specific embryo carries no copies, one copy or two copies of the abnormal gene i. PGD is useful when we know exactly what disease we are looking for. It is a truly diagnostic test whereas CCS is a screening tool.

CCS is extremely useful for couples that are at risk of chromosomal problems.