Removal of a single cell to perform PGD on a day 3 embryo.
At Yale, it is possible to increase the chance of successful pregnancy through techniques known as PGD (Preimplantation Genetic Diagnosis) and PGS (Preimplantation Genetic Screening). Both techniques involve the biopsy of an embryo to remove 1 cell if performed on day 3 or multiple cells if performed on day 5.
PGD is process by which embryos are screened for specific genetic defects in embryos before transferring them into the uterus. Following the genetic analysis of the biopsied cell, your physician will have valuable information to aid in the decision about which embryo(s) to transfer.
- Monogenic (single gene) disorders: these are diseases caused by mutations in specific genes. PGD can be used to avoid the risk of transmitting a genetic disease, such as cystic fibrosis, thalassemia, hemophilia, muscular dystrophy, etc. when one or both parents are carriers of a disease-causing mutation that could be transferred to offspring.
- Chromosomal rearrangement: PGD can be used to avoid the risk of transmitting a chromosomal defect, such as unbalanced translocation, inversion, or deletion when one of the parents carries a balanced chromosomal defect.
- Advanced maternal age: It is known that women approaching 40 are at a higher risk of having a baby with a chromosome abnormality (most notably Down's syndrome). With PGS, embryos are tested for chromosome defects before being transferred into the uterus.
- Multiple IVF failures: Failure to achieve a pregnancy after multiple cycles of IVF with embryo transfer can leave couples in a distressed state. PGS may help explain IVF failure.
- Recurrent spontaneous miscarriages: To reduce the risk of recurrent spontaneous abortions or miscarriage in couples that had 2 or more pregnancy losses due to aneuploidy of the fetus. Recurrent miscarriage is also common in couples where one or both are carriers of chromosomal defects (balanced translocations).
In order to perform PGD/PGS testing, the embryos must be accessible, and thus, In Vitro Fertilization (IVF) is required. PGD/PGS is offered to both fertile and infertile couples.
Our expert embryologists have been trained extensively to perform embryo biopsy.
In the recent years, PGD/PGS was revolutionized by the development of methods that are extremely accurate and efficient in testing specific gene mutations and aneuploidy from a single or very few cells. These procedures allow us to examine whether an embryo has the correct number of chromosomes or carry a disease-causing mutation. For example, they help detect embryos that have a high chance of carrying an extra chromosome 21 (Down's syndrome) or other common chromosomal problems that could lead to miscarriage.
The cells biopsied at Yale are sent to Genesis Genetics for state-of-the art testing.
The additional normal embryos can be frozen to be used to achieve a future pregnancy. Therefore, there will be no need for another IVF-PGD cycle if there are several normal embryos obtained in one cycle.
Please call our New Haven or Westport offices to arrange a consultation with one of our expert physicians. Make sure you mention that you interested in learning more about PGD/PGS. You are kindly requested to bring any Molecular Genetics Diagnosis documents you may possess to your first appointment. Such documents, if available, will help our physicians start the process. Don’t worry if you don’t have any of these records. We will arrange all of the necessary testing after your initial consultation.