Learning Materials

Preconception Genetic Carrier Screening

There are many genetic tests and genetic carrier screening options offered by fertility clinics and OBGYN offices. When you are considering having a baby, it is important to know which tests are available and which of those tests make sense for you.   

When you first decide to start trying to become pregnant, you should first go to your OBGYN or fertility physician. Your physician will counsel you about steps to take to optimize your health prior to conception and about discontinuing birth control. You may be asked to start monitoring your monthly cycle. Sometimes, your physician will suggest taking prenatal vitamins and folic acid and using an ovulation predictor kit. American College of Obstetricians and Gynecologists (ACOG) and American Society for Reproductive Medicine (ASRM) recommend offering genetic carrier screening tests to patients prior to conception. Genetic screening sounds expensive … but thankfully, because of the recent advancement in DNA sequencing, genetic companies have been able to lower the costs of genetic tests. This is fantastic for you and your purse strings!  

68.7% of women undergo genetic carrier screening in the preconception phase. If you do not partake in preconception screening, it can also be done during pregnancy but fewer options may be available at that point if you are found to carry a genetic mutation.  

The benefits of genetic carrier screening are huge. In the US, 3% of babies are born with abnormalities. Around 20% of these abnormal births are caused by single-gene disorders. The good news is that many of these single-gene mutations can be detected through preconception genetic carrier screening.  

Fertility clinics such as West Coast Fertility Centers offer patients the option for genetic testing. Some patients are considered higher risk and they are encouraged to move forward with genetic carrier screening, while some lower risk patients may opt not to go through genetic testing. It really depends on your individual circumstance. It is recommended to discuss genetic screening with your doctor to decide on the best course of action for you.  

Types of Tests: 

Polymerase chain reaction tests or PCR-based tests have a lower detection rate of disease-causing variants. Polymerase chain reaction tests analyze a short sequence of DNA.  

Expanded carrier screening: Screens for many genetic disorders simultaneously 

Next-generation sequencing: Tests for genetic abnormalities using less DNA and is typically less expensive, and you get test results more quickly  

Pan-ethnic Screening: Carrier testing for multiple conditions at once, at a significantly lower cost than if each of these tests were run separately

PGT-M: Preimplantation genetic testing for monogenic disease (also known as preimplantation genetic diagnosis or PGD). This test screens for single-gene mutations in embryos  

PGT-A: Preimplantation genetic testing for aneuploidy (also known as preimplantation genetic screening or PGS). This test screens for chromosomal abnormalities in embryos  

Reference

Committee Opinion No. 690: Carrier Screening in the Age of Genomic Medicine. (2017). Obstetrics and gynecology, 129(3), e35–e40. https://doi.org/10.1097/AOG.0000000000001951