10 Frequently Asked Questions About Genetic (Embryonic) Testing

1. Why should you seek genetic testing?Genetic testing can be beneficial for many reasons and helps to determine a couple’s viability for a healthy child. It can aid in determining the cause of frequent miscarriages or previously unsuccessful IVF cycles. Others may want to know if they are carriers of a chromosomal disorder, like Down Syndrome. Genetic testing can help diagnose causes of infertility, which can help clinicians to create an individualized treatment plan, tailored to a couple’s specific needs.
2. How does genetic testing work?Embryos are biopsied in order to gain information pertaining to their health. To biopsy means to remove cells from the embryo in order to study its genetic material. The best time to biopsy embryos is at the blastocyst stage, or five to seven days after fertilization, as it is not only safe for the embryo, but also provides the most accurate results. After the embryo is biopsied, the sample is taken to the laboratory and tested for genetic abnormalities, which are usually the result of too little or too many chromosomes.
3. How long does it take to get test results? After a biopsy is taken and laboratory tests are performed, it typically takes 7-10 days to receive your results.
4. What is the cause of chromosomal disorders?While the exact cause of chromosomal disorders is generally unknown, abnormalities typically occur during cell division (meiosis and mitosis). Meiosis describes the cell division of an egg and sperm during embryonic development. The egg and sperm each contribute 23 chromosomes, creating a combined total of 46 chromosomes to a pregnancy during the fertilization process. If errors occur during this process, the result can be cells with too little (monosomy) or too many (trisomy) chromosomes. Some pregnancies go to term with trisomies or monosomies, with genetic disorders as a result; however, most end in miscarriage.

   Another form of cell division that can cause genetic abnormalities is called mitosis. Mitosis is a term used to describe the division of all cells, excluding the egg and the sperm. Whereas meiosis is the division that begins before and during fertilization, mitosis occurs after fertilization. Mitosis creates an exact copy of a pair of chromosomes, and divides them in half, over and over again, until an entire fetus is created. If an error occurs during cell division in mitosis, chromosomes may not split equally. Like meiosis, this can create a pair with a missing chromosome (monosomy), or an extra chromosome (trisomy).

5. What are some risk factors for chromosomal disorders?The leading risk factor for chromosomal disorders is maternal age. If a mother will be 35 or older at the time of delivery, the baby is at a higher risk for a genetic disorder. This is because a woman is born with all of the eggs she will ever have, which begin to mature during puberty. As the woman ages, not only do her eggs age, but her number of viable eggs actually decrease. One theory argues that because eggs are aging along with the mother, they may already have an incorrect number of chromosomes at fertilization. Another theory states that errors in meiosis are more likely to happen as a result of older eggs.

   Another lesser risk factor for the development of chromosomal abnormalities is the way in which a woman processes folic acid. While this risk factor is still being explored, new research suggests that women who have difficulty processing folic acid may be predisposed to having a child with chromosomal abnormalities. This risk can be easily reduced with the consumption of prenatal vitals during pregnancy.

6. How do I know if I’m a carrier of a chromosomal disorder?Tests called carrier screenings can be performed to determine if you or your partner are carriers of chromosomal abnormalities. This test involves taking a sample of blood, saliva, or tissue from inside your cheek, and testing it for specific genes. If the test result is positive, this means that you carry the gene for a particular disease, like Cystic Fibrosis. If the test result is negative, this means that you do not carry that particular gene.
7. How do I know which type of genetic testing is right for me?There are two types of genetic embryo screenings: Preimplantation Genetic Screening (PGS) and Preimplantation Genetic Diagnosis (PGD).

   Preimplantation Genetic Screening is typically used to diagnose infertility related to advanced maternal age (over 35), recurrent miscarriages, gender selection, multiple unsuccessful IVF courses, and poor ovarian function in younger women.

   Preimplantation Genetic Diagnosis is typically used for couples who currently have or are carriers of genetic diseases. PGD can identify and differentiate between healthy embryos and carrier embryos. Identifying healthy embryos can help couples from passing chromosomal abnormalities to their children. Couples can expect to wait approximately 7-10 days to find out the results of these tests.

8. What is the difference between Preimplantation Genetic Screening (PGS) and Preimplantation Genetic Diagnosis (PGD)?PGS looks at the overall chromosomal health, or number of chromosomes, present in the embryo. A healthy embryo has 23 complete pairs of chromosomes, whereas an unhealthy embryo carries more or less than 23 chromosome pairs. Examples of chromosomal disorders include Down Syndrome, Turner Syndrome, and Klinefelter Syndrome, to name a few. PGS is the best choice for a couple who is looking to diagnose and treat fertility issues.

   PGD involves screening for specific genetic diseases, like the BRCA-1 and BRCA-2 genes which can lead to breast cancer. Other commonly screened diseases are Cystic Fibrosis and Muscular Dystrophy. PGD is the best choice for a couple who knows they are carriers of a genetic disease, and are looking to differentiate between healthy and unhealthy embryos before implantation.

9. Are genetic testing results always accurate?For most tests, there exists some level of false-positives and false-negatives. A false-positive occurs when the test results reveal the existence of an abnormality, but in fact, no abnormality exists. False-negatives present the opposite situation- they indicate no abnormalities, when there is in fact an abnormality.

   It is important to note that the rate of false-positives and false-negatives are relatively low for most commonly used genetic tests, but your physician should inform you of the rates related to each test performed.

10. How do I know if embryonic genetic testing is right for me?While many couples feel better informed and empowered by choosing to conduct embryonic genetic testing, some have reservations. Like any medical procedure or testing, you should always work closely with your physician to make a decision that is right for you and your family.

Why should I choose OC Fertility for my fertility needs?

At OC Fertility, we hold ourselves to incredibly high standards. We are committed to providing the highest quality, client-centered care, while making sure you feel comfortable and have the information to make the best decisions for you and your family.

We believe in open communication with our clients and make sure that all of your questions are answered to your satisfaction. We create individualized treatment plans, tailored to each client, and ensure that you understand all of the costs and commitments involved before you begin your treatment.

We also have our own state-of-the-art IVF center, so all of your needs can be met within our facilities. Our goal is to prepare patients for the challenging, yet rewarding fertility journey to grow their family, and to support you every step of the way.

How do I contact you?

Please give us a call to make an appointment at (949) 706-2229. Our experienced team of board-certified physicians would be happy to help you on your fertility journey.