Who Should Consider PGS/PGD?.
Overall, PGS helps to solve Embryos Problems and Gender Selection ，and it can increase pregnancy rates per transfer and reduce the risk of miscarriage, it applies to:
- Fertility & IVF after age 35 (age ≥35)
- You’ve experienced more than two miscarriages or the embryo developmental arrest (EDA);
- Repeated implantation failures (≥3 times);
- Previous birth of a child with chromosomal abnormalities;
- Couples known to be carriers of chromosomal abnormalities;
- Severe male factor infertility.
What’s is PGS/PGT-A screening?
PGS(Preimplantation Genetic Screen), Also known as 3rd generation IVF, Refers to Preimplantation Genetic Testing (PGT) to select embryos with normal chromosome numbers and structures, or to exclude embryos with known inherited single gene disorder before transferring back to the uterus, as an attempt to improve the implantation and pregnancy rate, and helping you have a successful pregnancy and a healthy baby.
PGS testing assesses all 24 pairs of chromosomes, including the two sex chromosomes (X and Y) that determine the embryo’s sex.
Having missing or extra chromosomes is called aneuploidy. Aneuploidy is not usually inherited, but it will involve any chromosome. The risk of fetal aneuploidy rises with increasing maternal age.
The latest medical research shows that:
Up to half of the eggs in women over 35 and up to 75% in women over 39 are chromosomally abnormal.
Chromosomal abnormalities (aneuploidy) are the most common cause of spontaneous Miscarriages
and Embryo Arrests, and also which results in birth defects
and mental retardation
of live birth.
What is PGD?
PGD(Preimplantation Genetic Diagnosis) involves genetic testing of an embryo for a specific gene mutation[s] when one or both biological parents is already aware of the existence of a genetic abnormality. PGD need to be considered in the following：
- PGD is recommended for couples that have a genetic predisposition and/or have any probability of passing down a known genetic abnormality.
- In addition, families that have a history of single-gene defects—such as cystic fibrosis, sickle cell anemia, and muscular dystrophy—can consider PGD testing.
What does PGS testing Entail?
The entire process of PGS consists of multiple steps, each step performed by different experts and laboratories：
- The first part is embryos are created, This part occurs at a Fertility Clinic；
- The second part is embryo biopsy；In Day 5 embryo biopsy, several (3 to 6) cells are removed for testing.Cells within a day 5 or day 6 embryo have separated into two types: cells which will form the fetus (inner cell mass) and cells which will form the placenta (trophectoderm). More cells can be removed at this stage (from the trophectoderm) without compromising the viability of the embryo, possibly leading to a more accurate test. Embryo biopsy is done the Fertility Clinic by their own lab.
- Courier the PGS specimens to an outside genetic laboratory for analysis, The following is are commonly used laboratories:
a. Igenomix (www.igenomix.com) in New York City, New York,
b. Reprogenetics (www.reprogenetics.com) in West Orange, New Jersey,
c. Genesis Genetics(www.genesisgenetics.org) in Plymouth,Michigan,d.
Others.
- Freezing of the embryos. Usually it takes over 24 hours before the results are available. Hence freezing of the embryos is necessary.Freezing of the embryos takes place at a fertility clinic.
- The final step, the thawing of a frozen embryo,and transfer the embryo back into the uterus.This step is finished by your IVF doctor.
