Podcast Summary
Podcast Summary for S2E2: The “Hidden Risks” During Preconception Planning
Yoyo Chu
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Full episode is available here (in Cantonese).
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What Is a Carrier?
Every person is born with two sets of genes — one inherited from each parent. On average, each person carries around three to five gene variants associated with recessive genetic disorders.
If only one copy of a gene carries a variant while the other copy is normal, the person will show no symptoms and appear completely healthy. This is known as being a “carrier.”
Carriers have absolutely no symptoms and no warning signs — most are entirely unaware of their carrier status.
If both partners happen to be carriers of the same condition, each pregnancy carries a 25% chance the child will be affected, a 50% chance the child will be a healthy carrier, and a 25% chance the child will be completely unaffected.
Hong Kong data suggests that approximately one in every twenty couples are both carriers of the same genetic condition.
What Is Expanded Carrier Screening (ECS)?
ECS is a genetic screening test conducted using a blood sample or saliva swab that can simultaneously screen for hundreds of serious recessive genetic disorders in a single test.
Conditions covered include Spinal Muscular Atrophy (SMA), Fragile X Syndrome, Congenital Adrenal Hyperplasia (CAH), and Thalassaemia, among others.
The purpose of ECS is not to assess either partner’s current health, but to identify in advance whether the couple’s genetic combination poses any notable risk worth addressing.
Knowing early gives couples the ability to plan and the power to make informed choices.
Discovering risks only after conception significantly narrows the available options and greatly increases emotional pressure.
If Both Partners Are Found to Be Carriers, What Are the Options?
Option A | Natural Conception + Prenatal Diagnosis: Conceive naturally, then use chorionic villus sampling (CVS) or amniocentesis during pregnancy to determine the foetus’s genetic status, and decide on next steps based on the results and personal values.
Option B | IVF + Preimplantation Genetic Testing (PGT-M): Screen embryos for the specific genetic condition before implantation, ensuring that only unaffected or carrier embryos are transferred.
Option C | Accept the Odds and Conceive Naturally: After fully understanding the risks, choose to accept the uncertainty and prepare mentally and medically for any outcome.
Option D | Use Donor Sperm or Eggs, or Consider Adoption: A direction that some couples may seriously explore.
Option E | Choose Not to Have Children: An equally valid and fully respected personal decision.
Genetic counselling follows the principle of non-directive counselling — the counsellor does not make decisions for the couple, but ensures that every decision is made on the basis of full understanding.
Important Considerations Before Undergoing ECS
Test Limitations: ECS cannot cover every known genetic condition. A normal result does not mean there is absolutely no genetic risk whatsoever.
Variants of Uncertain Significance (VUS): Reports may sometimes contain ambiguous findings. A genetic counsellor can help interpret these results, preventing unnecessary panic or inadvertent dismissal.
Timing: Ideally, ECS should be done before pregnancy, allowing ample time and space to consider all available options. Undergoing testing after conception significantly increases time pressure on decision-making.
Cost: ECS is a self-funded service in Hong Kong, with fees varying by package and provider. A genetic counsellor can help assess the most suitable option for each couple’s circumstances.
Emotional Readiness: Before proceeding, couples should confirm that both partners are prepared to face any result together. Genetic counselling is a process that requires the full and shared participation of both individuals.
Conclusion
The purpose of genetic counselling is not that something is wrong with a couple — it is that they have the right to understand their situation in advance and to make informed, empowered choices.
The role of a genetic counsellor is to translate complex genetic data into comprehensible options, guiding couples from the uncertainty of “hidden risks” towards the confidence and clarity of “informed planning.”
Next episode: NIPT, Amniocentesis and Chorionic Villus Sampling (CVS) – The Real Choices in Prenatal Genetic Diagnosis
GENE TALKS Podcast Disclaimer
The content of this podcast is provided for general educational and informational purposes only and does not constitute medical advice, diagnosis, or treatment of any kind.
If you have questions about your personal health, genetic test results, or medical decisions, you should consult a qualified healthcare or genetics professional.
Any cases, experiences, or opinions mentioned in this program reflect the personal views of the host, and do not represent the positions of any medical institutions or professional organisations.
While GENE TALKS and its host endeavor to provide accurate and reliable information, they are not responsible for any consequences arising from the use or interpretation of the content.
Our mission: to help you understand genetics — and yourself — not to replace professional judgment.