How accurate is preimplantation genetic screening?

This screening process is used to identify any genetic defects in the embryos, which are created during IVF or In-vitro fertilization before pregnancy. PGD is referred by doctors when any congenital abnormalities that both the parents or even anyone have. The PGD or Preimplantation Genetic Diagnosis helps them determine the same genetic abnormality as the embryo.

On the other hand, PGS or Preimplantation Genetic Screening distinguishes normal chromosomal embryos from abnormal chromosomal embryos. This is very much essential for In-vitro fertilization. In the case of standard IVF, the quality of the sperms is not checked before transplantation; thus, this process helps to know whether the sperms carry any genetic abnormalities or not.

This process also helps to select the chromosomally normal embryos for the future IVF procedure. This screening procedure achieves a healthy baby and a successful pregnancy. Therefore talk to your doctors about PGS and know how it can benefit you

How does this process work?

At the blastocyst stage, a biopsy is taken, which is usually on day five or day six of the embryo’s development. A number of four to six cells are taken out from a total number of 100 to 200 cells blastocyst to perform the biopsy. Preimplantation Genetic Screening or PGS analysis is achieved from the biopsy. During the process of biopsy, the embryos are kept frozen. They are held at the fertility clinic during the biopsy.

Each of the embryos is screened, thus helping to quantify the total number of chromosomes. There must be 23 pairs of chromosomes or 46 chromosomes in each sample where the egg source must contribute one set, and the sperm source must contribute the other.

The chromosomally normal embryos provide higher chances of implantation with higher chances of pregnancy, resulting in a healthy child. Chromosomally abnormal embryos offer fewer opportunities for plantation with low chances of pregnancy, and also sometimes, the newborn has genetic defects.

The embryo is said to be chromosomally abnormal if the screening analysis finds any deviation from the 23 pairs of chromosomes. If the embryo is not euploid or chromosomally regular, there will one or more extra or missing chromosomes. Chances of unsuccessful implantation, miscarriage, or the birth of a child with genetic defects are higher.

A genetic report is made after analysis of all the embryos and further sent to the reproductive endocrinologist. Your doctor will decide which embryo to be transferred during IVF after the results are combined with morphology/grading.

Who is considered for PGS?

Frozen embryo success rates are much higher after the preimplantation genetic screening. This is just an additional step done during the process of IVF. Failed transfers and miscarriages are reduced at a higher percentage after this screening is done.

The abnormality in the chromosomes increases with the increased age of women. If the age of a woman is above 35, she must discuss PGS’s process with her doctor. But there is also a high risk of error in the chromosomes of the embryos of young women.

PGS is recommended to every woman despite the age, especially to those who had repeated miscarriages in both the cases of conceiving naturally or with the help of fertility.