Genetic Testing

Understanding Genetic Testing in Fertility Treatment

If you're planning to start a family—especially through fertility treatments like in vitro fertilization (IVF) —genetic testing can offer important information. These tests help you learn about possible risks of passing on inherited conditions, improve the chances of a successful pregnancy, and support the birth of a healthy baby. The following information provides a guide to the different types of genetic testing you might encounter during fertility care.

Carrier Screening – Before Conception

What it is: A test performed on blood or saliva that determines if you or your partner carry genes for certain inherited diseases—many of which you might not even know you carry.

Why it matters: If both you and your partner carry the same gene for a condition (like cystic fibrosis or sickle cell disease), there’s a chance your baby could be born with the condition.

When it’s done: Before you try to become pregnant.

Next steps if you are both carriers: You may consider options like IVF with special testing (Preimplantation Genetic Testing), using donor eggs or sperm, or further testing during pregnancy.

Preimplantation Genetic Testing (“PGT”) of Embryos – During In Vitro Fertilization Treatment (IVF)

What it is: A way to check the health of embryos before they are placed into the uterus during in vitro fertilization (IVF). Embryos can be tested in a highly-specialized genetics laboratory to determine which are the healthiest embryos and suitable for embryo transfer. There are three primary types of embryo testing: PGT-A, PGT-M, and PGT-SR.

• PGT-A (the “A” stands for “aneuploidy”): Determines if an embryo has the correct number of chromosomes; this is called a “euploid” or normal embryo. Or if an embryo has too many or too few chromosomes; this is called an “aneuploid” or abnormal embryo. Aneuploid embryos have a very strong risk of developing abnormally and/or causing a miscarriage, and should not be transferred to the uterus.
• PGT-M (the “M” stands for “monogenic”): If you and/or your partner are carriers of a specific inherited disease caused by a single gene (e.g. Huntington’s Disease, Duchenne Muscular Dystrophy, certain types of cancer) this test determines which embryos inherited that disease (termed “affected”), and which embryos did not (“unaffected”). 
• PGT-SR (the “SR” stands for “structural rearrangements”): Individuals can have abnormalities in the way their chromosomes are structured (e.g. translocations, inversions, deletions, or duplications). These individuals are at higher risk for infertility and miscarriage. If the chromosomal rearrangements are passed to their offspring, those children are at risk for birth defects and genetic disorders. Testing of the embryos determines which ones do and do not have the structural rearrangements. 

How it works: Embryos are created through in vitro fertilization and are cultured in the embryology lab until they reach a size safe for biopsy. A few cells are carefully removed from the portion of the embryonic structure that will become the placenta. These cells are sent to a highly specialized laboratory for genetic analysis. The embryos remain frozen until the testing is completed, typically two to four weeks. Only healthy embryos are chosen for transfer.

Prenatal Genetic Testing – During Pregnancy

If you're already pregnant, there are tests that can be performed to check your baby’s genetic health: NIPT, CVS, and Amniocentesis.

NIPT (non-invasive prenatal testing): A simple blood test from the mother after 10 weeks of pregnancy. It checks for common chromosome conditions.

CVS (chorionic villus sampling): A small sample of placental tissue, called chorionic villi, is taken usually between 10 to 13 weeks of pregnancy. Sampling can be done through the cervix or through the mother’s abdomen.

 Amniocentesis: This is a more detailed test done later in pregnancy, usually between 15 to 20 weeks. A thin needle is inserted through the mother’s abdominal wall into the uterus. A small amount of amniotic fluid or placental tissue is removed for genetic analysis.

Genetic testing should always be a personal decision and choice. You and your partner decide what’s right for yourselves. When considering testing, it is advisable to consider a consultation with a genetic counselor who can help you understand test results and guide you through your options. Costs and insurance coverage for these procedures is extremely variable. Our financial counselor can help you navigate cost and coverage questions.

Genetic testing during fertility care gives you more information and more choices. Whether you're just starting to think about having a baby, already doing IVF, or are pregnant, these tests can help you make informed decisions for your future family.