PGD Testing and Treatment

Texas IVF

1-866-IVF-Texas
1-866-483-8392

Dr. Rodriguez of Texas IVF uses the Microarray technology for IVF

At Texas IVF, Dr. Alfred J. Rodriguez now offers the most technologically advanced method of preimplantation genetic testing by CGH microarray. Microarray analysis allows for molecular karyotyping for all 23 pairs of chromosomes, and assessment for both aneuploidy (abnormal number of chromosomes) and structural abnormalities (changes that alter the content of chromosomes).

This minimizes the risk of passing known or suspected genetic disorders and helps identify healthy embryos which improves the likelihood of a successful IVF outcome. Patients that may benefit from testing are those with a family history of genetic disorders, history of recurrent pregnancy loss, long term unexplained infertility, multiple unsuccessful IVF cycles, advanced maternal age, and severe male factor infertility.

PGS and PGD – often used interchangeably but incorrectly.

 

PGS is preimplantation genetic screening and is testing to confirm that the correct number of chromosomes (46) is present in an embryo.  When there is an extra chromosome present (trisomy) conditions such as Down’s Syndrome (trisomy 21) is diagnosed.

 

PGD is preimplantation genetic diagnosis and is a screen for a specific genetic disorder such as Cystic Fibrosis.  Preparing for PGD can take weeks or months as the genetics laboratory will need to develop a “probe” to test for specific genetic disorder. This will require blood samples from both partners and possibly other family members to develop the probe needed to test for a specific disorder.  Additionally, a consultation with the genetic counselor for the laboratory will be required to fully discuss your particular gene disorder, as well as sign all the necessary permits and make financial arrangements.

 

Many question as to whether PGS/PGD increases the chance of pregnancy, but overwhelmingly, the answer to this is YES!  Many miscarriages occur as the result of a chromosomally abnormal embryo.  If testing for a single gene disorder, the recommendation is to do aneuploidy screening as well. Combining the two (PGD/aneuploidy screen) have shown to reduce the risk of miscarriage and improve overall outcome of IVF.

 

Of course, many factors must be considered for each:

 

  1. What determines which embryos can be biopsied?

 

Embryos must reach a stage of development in order to withstand the biopsy procedure.  Embryos are graded based on expansion, quality of the trophectoderm (which will eventually form the placenta) and the inner cell mass that becomes the fetus.  An embryo must be fully expanded in order to undergo trophectoderm biopsy.  This stage is usually reached by day 5 or 6 after fertilization.

 

  1. How many embryos are needed to perform biopsy?

 

There is no set number needed.  This depends on the individual patient and their specific clinical situation.  Should a couple decide they desire more embryos tested than obtained in a single cycle, the samples collected will be stored/banked until more embryos are obtained for biopsy from subsequent IVF cycle(s).  PGS can be performed even if only one biopsy meets criteria.  There are labs that offer testing fees based on “per embryo” instead of the typical lab testing fees which are the same whether 1-8 embryos are tested.

 

  1. Does biopsy of the trophectoderm damage the embryo?

 

Trophectoderm biopsy is performed on embryos that have many cells- around 200-300. Because of the advanced stage of development, approximately 4-6 cells are removed from the trophectoderm layer causing very little trauma to the embryo.  A healthy, advanced stage blastocyst can usually easily withstand the removal of few cells and undergo cryopreservation and subsequent thawing.  Diagnosis error is much less with trophectoderm biopsy- approximately 97% accuracy.

 

  1. What happens to the embryo after biopsy?

 

The embryo(s) are quickly frozen (vitrified) thus allowing time for testing to be completed.  Vitrification has been a “game changer” as the cryoprotectants used for this “flash freezing” method lower the freezing point and help prevent intracellular ice crystal formation which are damaging to the cells of the embryo.  Upon thawing, most vitrified embryos are virtually indistinguishable from fresh embryos.


  1. How long before information is available on tested embryos?

 

For routine chromosomal testing for aneuploidy, the turn-around time is 3-5 business days.  For single gene disorders, results can take up to 2-3 weeks.  Our office will contact you once results are reported to us.

 

  1. When will preparation for transfer of embryo(s) begin?

 

Generally, preparation can begin with the first menses after retrieval cycle and confirmation of normal (euploid) and/ or unaffected embryos are available for transfer.

 

The take home message regarding PGS/PGD testing is that both provide very high pregnancy rates, by allowing for the transfer of a single, chromosomally tested, normal embryo. It must be made clear that the transfer of a normal euploid embryo does not guarantee a pregnancy.  There are many factors involved in implantation that goes beyond normal (euploid) chromosomes.  The embryo must have the necessary cellular integrity to undergo all phases of implantation and the endometrium must be in the receptive “window of implantation”.

 

For more information about the Preimplantation Genetic Testing / Screening (PGD) program or to schedule an appointment with Dr. Alfred J. Rodriguez at Texas IVF, please call us directly at 1-866-483-8392 or simply fill out our online form and we will contact you at your convenience.

Contact Info

6130 West Parker Road
Suite 215
Plano, TX 75093-8185

Telephone: 972-981-7800
1-866-IVF TEXAS
(1-866-483-8392)
Fax: 972-981-7814

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