At a glance
Learn how genetic carrier screening works, why it may be considered before IVF, and what to discuss with a genetic counselor in Thailand.
What Is Genetic Carrier Screening?
Genetic carrier screening is a blood or saliva test that looks for changes (variants) in genes that can cause certain inherited conditions. If you carry a variant for a condition, you usually do not have the condition yourself, but you may pass the variant to your children. When both partners carry a variant in the same gene, there is a chance their child could inherit the condition.
Carrier screening can be done before pregnancy or as part of your IVF planning. It is not a routine test for everyone, and it does not screen for all possible genetic conditions. The decision to have carrier screening is personal and should be made with the help of a genetic counselor or healthcare provider.
At a Glance: Key Points
- Carrier screening identifies genetic variants that may not affect you but could affect your children.
- It is most informative when both partners are tested.
- Results can help you understand reproductive options, including IVF with preimplantation genetic testing for monogenic disorders (PGT-M).
- Carrier screening is not a guarantee of a healthy baby and does not replace other prenatal tests.
- In Thailand, carrier screening is available in many fertility centers, but availability and panels vary.
How Carrier Screening Relates to IVF and PGT-M
If you are planning IVF, carrier screening results may influence your treatment plan. For example, if both partners are carriers for the same autosomal recessive condition, you may consider IVF with PGT-M. PGT-M is a technique used to test embryos for a specific genetic condition before transfer. It is not a routine add-on for all IVF patients; it is used when there is a known risk of passing on a particular genetic disorder.
Carrier screening is not the same as PGT-A (preimplantation genetic testing for aneuploidy), which screens embryos for chromosomal abnormalities. PGT-M is targeted to a specific gene, while PGT-A looks at chromosome number. Some patients may have both types of testing, but the decision depends on your medical history and reproductive goals.
What Does Carrier Screening Test For?
Carrier screening panels vary. Some test for a few common conditions, while expanded panels may screen for hundreds of conditions. In Thailand, the specific panel offered will depend on the laboratory and clinic. Common conditions screened include cystic fibrosis, spinal muscular atrophy, thalassemia, and others, but the exact list varies.
It is important to ask your clinic which conditions are included in the panel and whether it is tailored to your ethnic background. Some genetic conditions are more common in certain populations, and a genetic counselor can help you understand which panel may be most relevant for you.
What Do Results Mean?
Carrier screening results can be positive, negative, or inconclusive. A positive result means you carry a variant for a condition, but it does not mean you have the condition. A negative result reduces the likelihood that you are a carrier for the conditions tested, but it does not eliminate all risk. Inconclusive results are rare but may require further testing.
If both partners are carriers for the same condition, the chance of having an affected child is 25% with each pregnancy. This is a statistical chance, not a certainty. A genetic counselor can explain your specific results and what they mean for your family planning.
Carrier Screening in Thailand: What to Consider
If you are considering carrier screening in Thailand, here are some points to discuss with your clinic:
- Which genetic conditions are included in the screening panel?
- Is the test performed in Thailand or sent to an overseas laboratory?
- How long will it take to receive results?
- Will a genetic counselor be available to explain the results?
- How do results affect your IVF treatment plan, if at all?
Costs for carrier screening can vary widely, and insurance coverage may not apply. It is best to ask for a detailed quote and check whether the fee includes counseling.
Questions to Ask Your Clinic
- What type of carrier screening do you offer, and what conditions does it cover?
- Do you recommend carrier screening for all IVF patients, or only for those with a family history?
- If we both are carriers, what are our options for IVF and PGT-M?
- Are there any limitations to the screening test?
- Can we meet with a genetic counselor before and after testing?
Next Steps: Your Checklist
- Discuss your family history and any known genetic conditions with your healthcare provider.
- Ask your fertility clinic about carrier screening options and whether they recommend it for you.
- If you decide to proceed, arrange for both partners to be tested.
- Plan to review results with a genetic counselor to understand your options.
- Consider how results may affect your IVF timeline and treatment decisions.
Carrier screening is a personal choice. It can provide useful information, but it is not required for everyone. Always seek guidance from qualified professionals who can interpret your results in the context of your overall health and reproductive plans.
Frequently asked questions
Is genetic carrier screening necessary before IVF?
Carrier screening is not necessary for everyone. It is recommended when there is a family history of a genetic condition, or when you want more information about your risks. Discuss with your doctor whether it is appropriate for you.
What is the difference between carrier screening and PGT-M?
Carrier screening tests parents to see if they carry a gene variant. PGT-M tests embryos for a specific genetic condition before transfer. Carrier screening can identify couples at risk, and PGT-M can help select embryos that do not have the condition.
Can carrier screening be done in Thailand?
Yes, many fertility clinics in Thailand offer carrier screening. The availability of specific panels may vary, so ask your clinic about the tests they provide.
What if both partners are carriers for the same condition?
If both partners are carriers for the same autosomal recessive condition, there is a 25% chance with each pregnancy that the child will be affected. You may consider IVF with PGT-M to test embryos for that condition. A genetic counselor can explain your options.
Continue your research
Medical information notice: This article is educational and does not replace individual assessment, diagnosis, genetic counselling or treatment advice from a licensed clinician. Provider services, availability, fees and policies should be verified directly before booking.
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