PGD / PGS

Preimplantation Genetic Testing

Preimplantation genetic testing refers to the genetic testing of embryos prior to when they are placed in the uterus. Both PGD/PGS involve the same technique for the removal of a cell from an embryo that was created using In vitro fertilization (IVF). This testing is performed in order to determine if certain genetic anomalies are present in the embryo such as genes for diseases (PGD) or abnormal chromosome number known as aneuploidy (PGS).

PGD: Preimplantation Genetic Diagnosis

Preimplantation Genetic Diagnosis, or PGD, is a diagnostic procedure in which embryos are tested for genetic abnormalities. Screening for a genetic illness can be done by performing PGD for a single gene mutation. In this situation, the embryos are screened not for a chromosomal problem, but for a single gene abnormality associated with a single disease.  Thousands of gene loci have been identified. Certain illnesses are carried as traits by parents. When both traits are passed on to a child, she or he can be affected. Yet, for many such illnesses, carrier status can be diagnosed prior to conception. Both family history and ethnic background help to determine which testing may be appropriate for you. PGD screenings for single gene defects have been carried out for scores of genetic illnesses, including: cystic fibrosis, Huntington’s chorea, Marfan syndrome, Tay-Sachs and Sickle Cell Anemia.

PGS: Preimplantation Genetic Screening

PGS, Preimplantation Genetic Screening is when embryos are tested for chromosomal abnormalities. Chromosomes are sub-cellular structures that house one’s genes. All of the information that is needed to lead to an individual’s development is contained on these chromosomes and each one of us has 23 pairs of them. During human reproduction, it is not unusual to produce embryos that have too few or too many chromosomes, this is known as “aneuploidy”. PGS, also commonly referred to as Aneuploidy Screening is used to screen for commonly encountered embryonic chromosomal disorders.  Infertile couples may benefit from this test if the female partner is older, if they have had several failed IVF cycles, or  if they suffer from repetitive older miscarriages.

How to Determine if You Need PGD/PGS Testing?

The physicians of Chelsea Fertility NYC have long-term experience as they are some of the first in the field to utilize this technology and are published in this area as well. At Chelsea Fertility NYC, we perform PGD and PGS as indicated:

  • (A) Patients with in-born errors of metabolism (i.e. Tay-Sachs, Gaucher’s)
  • (B) Patients that carry genetic markers for known diseases (i.e. cystic fibrosis, hemophilia, sickle cell anemia, muscular dystrophy, etc.)
  • (C) Patients with unexplained miscarriages (over 60% of repetitive miscarriages are due to aneuploidy)
  • (D Embryo screening to de-select aneuploidy electively
  • (E) Gender identification prior to embryo transfer electively

The PGD/PGS Process

The embryo is developed for five days in the lab after egg harvesting and fertilization. The outer area of cells, known as the trophoblast (not destined to be the baby) is biopsied. A few cells are removed from over one hundred at this location. The embryo is not harmed or compromised, but occasionally its growth may be arrested. For (PGD) genetic diseases (A-B), the cells are analyzed for markers of these diseases. The embryos are frozen while awaiting results, which can take a few days. Once the normal embryos that do not carry the genetic disease are identified, the embryos can be subsequently thawed and transferred back without any decrease in success from being frozen. For (PGS) aneuploidy screening (C-E), the cells are analyzed within 24 hours with results of up to all 23 chromosomes and sex chromosomes.  This assessment of the integrity of the genetic composition of the embryo allows for a more correct decision as to what embryo to transfer.  The embryo is also best frozen and transferred during a subsequent cycle. *Please note that if needed, both PGD and PGS can be done on the same biopsy.

Talk to Your Fertility Specialist about PGD/PGS

The fertility specialists at Chelsea Fertility NYC have extensive experience with Preimplantation Genetic Testing options, including PGD and PGS.  The initial step involves in-depth testing and analysis to determine the indication for these options and to review alternatives. We invite you to contact Chelsea Fertility NYC to request an initial genetic testing consultation.

Frequently Asked Questions about PGD/PGS:

Can PGD/PGS help improve IVF success rates?
This is a controversial issue as patient selection (age, indication) does determine its efficacy. PGS or PGD can cause a transient stunting to the growth of the embryo and may decrease the overall pregnancy rate in young patients (less than 35 years of age) who would otherwise not need this procedure. For this reason, PGD/PGS screening(s) are not routinely done unless there is a history of repetitive pregnancy loss (miscarriages) in the younger patients or a medical indication for PGD. For all patients with RPL, regardless of age, this can increase the chances of a live birth.

PGD is done for genetic disease removal from the embryo so the resultant child will not be afflicted, and therefore is indicated when the goal is to do so. Older patients with increased risk of aneuploidy may benefit from PGS as well. Your physicians at Chelsea Fertility NYC are experienced with this and fully understand the complexities and value of PGD/PGS. We will make sure you are informed completely to allow you to make the best decision in your management.

How much is PGD/PGS? Can the cost be covered by insurance?
This is a variable among providers, but Chelsea Fertility NYC center does offer competitive packages to consider should your insurance not cover this service.
Are there any risks involved with PGD/PGS?
To date, there are no known risks associated with the procedure that would add to the risks associated with infertility or IVF in general.
Do PGD/PGS replace prenatal testing?
We would still advise amniocentesis or chorionic villus sampling as indicated for the pregnancy.
Can PGD/PGS be used for gender selection?
Yes, PGS is used for screening out genetic abnormalities, such as chromosomal abnormalities and documenting the gender and normalcy of the sex chromosomes.

PGD: Suggested Genetic Screening

By Ethnicity:

  • Northern European:
    • CF- molecular testing for common mutations (specify ethnicity)
  • African:
    • Sickle cell Anemia-hemoglobin electrophoreisis
    • Alpha-thalassemia-Complete blood count for MCV
    • Beta-thalassemia-Complete blood count for MCV
  • Caribbean or Latin American:
    • Sickle Cell Anemia-hemoglobin electrophoreisis
  • Southeast Asian:
    • Alpha- thalassemia-Complete blood count for MCV
    • Beta-thalassemia-Complete blood count for MCV
  • Indian or Pakistani:
    • Beta-thalassemia-Complete blood count for MCV
    • Sickle cell Anemia-hemoglobin electrophoreisis (Indian)
  • Middle Eastern:
    • Sickle cell Anemia-hemoglobin electrophoreisis
  • Mediteranian (Sardinia and Cyprus)
    • Beta-thalassemia-Complete blood count for MCV
    • Sickle cell Anemia-hemoglobin electrophoreisis
  • French Canadian/Acadian:
    • CF-molecular testing for common mutations (specify ethnicity)
    • Tay Sachs Disease-serum hexaminodase level
  • Ashkenazi Jewish-consider genetics counselling:
    • CF-molecular testing for common mutations (specify ethnicity)
    • Tay Sachs Disease-serum hexaminodase level
    • Canavan Disease-molecular testing for common mutations (specify ethnicity)
    • Gaucher Disease- molecular testing for common mutations (specify ethnicity)
    • Niemann-Pick
By Condition:

  • Cystic Fibrosis
    • Ashkenazi Jewish
    • French Canadian
    • Northern European Caucasion
  • Alpha-Thalassemia
    • Southeast Asian
    • African
  • Beta-Thalassemia
    • Mediteranian (Sardinia and Cyprus)
    • Southeast Asian
    • Indian (East)
    • Pakistani
    • African
  • Sickle Cell Anemia
    • African
    • Mediteranian (Sardinia and Cyprus)
    • Middle Eastern
    • Caribbean
    • Latin American
    • Indian
  • Tay-Sachs
    • Ashkenazi Jewish
    • French Canadian/Acadian
  • Canavan Disease
    • Ashkenazi Jewish
  • Gaucher Disease
    • Ashkenazi Jewish
  • Niemann-Pick