PGT for Genetic Abnormalities
Couples undergoing any kind of fertility therapy should be sure that they have had genetic screening. For couples who are found to be at risk for transmitting a known genetic condition to their children, PGT can help them build a healthy family. Advances in reproductive medicine now make it possible to screen embryos for certain genetic abnormalities before a pregnancy even begins. This process is known as Preimplantation Genetic Testing, or PGT.
PGT is performed during in vitro fertilization (IVF). It allows doctors to examine embryos for specific genetic problems and to select those most likely to develop into a healthy child. For many families, this technology offers a way to avoid passing on a serious inherited disease, or to reduce the risk of miscarriage caused by chromosomal errors.
At the same time, PGT raises important medical and halachic questions. Understanding how the process works, what it can and cannot do, and how Jewish law views it will help you make thoughtful, informed decisions. We at PUAH are here to guide you through every step.
What Is PGT?
PGT is a laboratory technique used to test embryos created through IVF before they are placed in the uterus. A few cells are gently removed from each embryo and analyzed in a genetics lab. Embryos found to be free of the targeted condition can then be selected for transfer.
There are three main types of PGT, each designed for a different purpose:
PGT-M (Monogenic): Tests for a single-gene disorder that one or both parents carry, such as Tay-Sachs disease, cystic fibrosis, or Gaucher disease.
PGT-SR (Structural Rearrangements): Used when a parent carries a chromosomal rearrangement, such as a translocation, that can lead to miscarriage or birth defects.
PGT-A (Aneuploidy): Screens embryos for an abnormal number of chromosomes, which becomes more common with advancing maternal age.
When Is PGT Considered?
PGT is not part of routine fertility treatment. It is typically recommended in specific situations where there is a meaningful genetic risk. You may want to consider PGT if any of the following apply to you:
Known Carrier Status
When both partners are carriers of the same recessive genetic disease, each pregnancy carries a one-in-four chance of an affected child. Carrier screening — common in many Jewish communities — often reveals these risks before a couple begins trying to conceive. PGT-M can help such couples select embryos that are not affected.
Family History of Genetic Disease
If a serious inherited condition runs in your family, testing can identify embryos at risk and reduce the chance of passing the condition to a child.
Recurrent Pregnancy Loss
Repeated miscarriages are sometimes caused by chromosomal abnormalities. In certain cases, PGT may help identify embryos with the correct chromosome count.
Chromosomal Rearrangement in a Parent
A parent who carries a balanced translocation is usually healthy but may produce embryos with missing or extra genetic material. PGT-SR can help identify embryos that are properly balanced.
How the Process Works
PGT begins with a full IVF cycle. The basic steps include:
Ovarian stimulation: Medication encourages the ovaries to mature several eggs.
Egg retrieval and fertilization: Eggs are collected and fertilized in the laboratory.
Embryo culture: The embryos grow for several days until they reach the blastocyst.
Biopsy: A small number of cells are carefully removed from each embryo for testing. It is important to note that not every embryo is eligible for biopsy. Most often, embryos that do not survive to day 5 or 6 are discarded.
Genetic analysis: The lab examines the cells for the targeted condition. This genetic analysis is considered to have an accuracy of >99% for the condition tested.
Embryo transfer: After biopsy for PGT, the embryos may be evaluated for transfer, and an unaffected embryo is selected and transferred to the uterus. The remaining suitable embryos may be frozen for future use.
Benefits and Limitations
PGT can significantly reduce the chance of having a child with a known genetic condition and may shorten the emotional path to a healthy pregnancy. It can also reduce the likelihood of certain miscarriages.
It is important, however, to understand the limits of this technology. PGT does not guarantee a healthy baby, because it tests only for the specific conditions being screened. It cannot detect every possible genetic or developmental problem. The biopsy carries a very small risk to the embryo, and results are occasionally inconclusive. Because PGT requires IVF, couples who could otherwise conceive naturally must still undergo a full treatment cycle.
Halachic Perspective
Jewish law places great value on the building of a family and on protecting health and life. For this reason, the use of PGT to prevent the birth of a child with a serious genetic disease is, in many circumstances, viewed favorably by halachic authorities. The ability to avoid grave suffering is a meaningful consideration in Jewish thought.
At the same time, PGT involves several sensitive halachic issues. These include the creation of embryos through IVF, the handling and possible discarding of embryos that are affected or not used, and questions of supervision to ensure proper lineage and to avoid any mix-up of genetic material. The acceptability of testing for less severe conditions, or for non-medical purposes, must be weighed carefully and individually.
Because each situation is unique — depending on the specific condition, its severity, the couple's circumstances, and the practical details of the treatment — these matters cannot be decided by general rules alone. Halachic guidance should accompany the medical process from the very beginning.
PUAH's team of doctors and rabbis specializes in exactly these situations. We can help coordinate proper halachic supervision in the laboratory and ensure that the entire process is conducted with care and integrity. Specific questions should be discussed with a qualified rabbinic authority. Our team at PUAH is available to help you navigate these questions.
When to Speak With a Professional
You should consider speaking with a genetics professional and a fertility specialist if you and your partner are known carriers of the same condition, if a serious genetic disease runs in either family, if you have experienced recurrent miscarriages, or if a parent carries a chromosomal rearrangement. Genetic counseling can clarify your specific risks and help you understand whether PGT is appropriate for you.
Equally important is reaching out for halachic guidance early. Because PGT involves decisions that touch on Jewish law at multiple stages, it is best to seek direction before treatment begins. Our advisors at PUAH can help you bring together the medical and halachic sides of this journey with confidence.
Summary
PGT allows couples undergoing IVF to test embryos for specific genetic abnormalities and to select healthy embryos for transfer. While it offers real hope for families at risk of passing on serious inherited diseases, it also raises medical limitations and important halachic considerations. With proper guidance, you can make decisions that honor both your health and your values.
Disclaimer: This article is intended for educational purposes only and should not replace medical advice from a qualified healthcare professional. Personal halachic questions should be discussed with a qualified rabbinic authority.