Going to Hong Kong for IVF to Avoid Passing on Genetic Diseases: Key Procedures and Medical Evaluation

When is it suitable to go to Hong Kong for PGT IVF to avoid genetic diseases?

For couples with a clear risk of genetic diseases, using Preimplantation Genetic Testing (PGT) technology in Hong Kong is currently a medically achievable preventive measure. However, not all genetic diseases are suitable, nor does everyone need it.

Suitable situations:

• Couples who are carriers of monogenic diseases (e.g., SMA, thalassemia, hemophilia, cystic fibrosis) with a clearly identified pathogenic gene.
• Carriers of chromosomal structural abnormalities (e.g., balanced translocation, Robertsonian translocation, inversion) with a history of recurrent miscarriage or children with abnormalities.
• Carriers of sex chromosome-linked genetic diseases (e.g., DMD, Fragile X syndrome) requiring embryo sex selection.
• Those with a clear family history of genetic disease but who have not been tested themselves, and for whom PGT is deemed necessary after genetic counseling evaluation.
• Those who have had a previous pregnancy terminated due to a genetic disease or have given birth to a child with a genetic disease and wish to avoid recurrence.

Unsuitable situations or those requiring careful evaluation:

• Diseases with unclear pathogenic genes or complex inheritance patterns (e.g., some polygenic diseases, mitochondrial diseases).
• Both partners have not undergone carrier screening, making it impossible to identify specific pathogenic loci.
• Women with severely diminished ovarian reserve (AMH < 0.5 ng/mL, antral follicle count < 4), making it difficult to obtain enough embryos for testing.
• Advanced maternal age (female > 42 years), where the high rate of embryonic aneuploidy may result in no viable embryos for transfer after PGT.
• Presence of genetic variants that PGT technology cannot detect (e.g., some dynamic mutations, methylation abnormalities).

The Medical Logic of Genetic Diseases and PGT

The transmission of genetic diseases within a family essentially involves the passing of pathogenic genes or chromosomal abnormalities to offspring through gametes (eggs or sperm). Conventional prenatal diagnosis (amniocentesis, chorionic villus sampling) is a form of "pregnancy screening," where discovering a problem often leads to the difficult decision of terminating the pregnancy.

PGT technology completes genetic testing before the embryo is implanted into the uterus, prioritizing the transfer of embryos that do not carry the pathogenic gene, thus blocking the transmission of genetic diseases at the source. Hong Kong started early in the field of PGT, with successful cases in the early 2000s. Its regulatory framework is relatively clear, and laboratory quality control standards are in line with international norms.

Why choose Hong Kong: Hong Kong regulates PGT through a "case-by-case approval system," requiring submission of genetic counseling reports, family verification results, laboratory qualification documents, etc. The approval cycle is typically 2-4 weeks. Compared to some centers in Mainland China, Hong Kong has certain advantages in the range of monogenic diseases covered and the depth of testing, but the costs are correspondingly higher.

Reproductive Doctor's Evaluation Process

From a clinical perspective, a doctor's evaluation of whether a family with a genetic disease is suitable for PGT in Hong Kong usually follows five steps:

1. Confirmation of Genetic Cause: It is essential to obtain the genetic test report of the proband (affected family member) or both partners to identify the pathogenic gene and mutation site. If there is no clear diagnosis, a genetic clinic evaluation must be completed first.
2. Family Verification: Most PGT-M (monogenic disease testing) requires blood samples from the proband or parents to establish testing probes. This step is often overlooked but is crucial for determining whether PGT can proceed.
3. Fertility Assessment: Check the woman's AMH, FSH, and antral follicle count, and the man's semen analysis. The goal is to determine whether a sufficient number of embryos can be obtained for testing.
4. Genetic Counseling and Informed Consent: Inform about the limitations of PGT—a testing error rate of approximately 1-2%, the risk of having no embryos available for transfer, and the need for prenatal diagnosis after transfer for confirmation.
5. Protocol Development and Referral: If the decision is made to go to Hong Kong, contact the Hong Kong reproductive center, submit all examination materials, and have the laboratory there evaluate the feasibility of the testing.

Doctor's perspective: PGT is not a "universal vaccine"; it only addresses known genetic risks and cannot prevent all birth defects. For families with clear genetic indications, it is an effective medical intervention, but success rates and limitations must be viewed rationally.

The Impact of Age on PGT

Female age is one of the most critical variables affecting PGT success rates, primarily in terms of the number of eggs retrieved and the embryonic aneuploidy rate.

For older women (especially those over 40), going to Hong Kong for PGT requires mental preparation for the possibility that "no embryos may be available for transfer." Some centers may recommend combining PGT-A with PGT-M testing simultaneously to maximize the use of limited embryos.

Main Differences Between Hong Kong and Mainland China for PGT

Families choosing to go to Hong Kong for PGT often value the following differences:

Selection advice: If the genetic disease is already within the routine PGT testing scope in Mainland China and there is a qualified local reproductive center, it is preferable to seek treatment nearby. If the disease is rare, testing is complex, or a more comprehensive genetic consultation is desired, Hong Kong can be considered as an alternative.

Five Key Details Most Easily Overlooked

Based on actual cases, the following details are often overlooked but can affect the success or failure of the entire PGT cycle:

• Family blood samples must be collected before starting: Blood samples from the proband or parents are the basis for establishing testing probes. If the proband has passed away or cannot provide a sample, alternatives (e.g., preserved pathological tissue) must be used, significantly increasing testing difficulty.
• Genetic counseling reports need to be bilingual (Chinese and English): Hong Kong centers usually require English genetic reports. Reports issued in Mainland China need to be translated and notarized in advance.
• Precise coordination between the testing window and egg retrieval time: Probe preparation for PGT-M takes 2-4 weeks and must be synchronized with the ovarian stimulation cycle. If probes are not completed on time, all embryos must be frozen and wait.
• Embryo mosaicism: Approximately 5-10% of embryos are mosaic (a mix of normal and abnormal cells). PGT results may not 100% represent the true status of the embryo, requiring final confirmation through prenatal diagnosis after transfer.
• Legal requirements in Hong Kong: Hong Kong stipulates that PGT is only for medical indications and does not allow non-medical sex selection or "designer babies." All testing protocols must pass ethical review.

Specific Process for PGT IVF in Hong Kong

A complete PGT cycle in Hong Kong, from initial consultation to transfer, typically takes 3-5 months. The general process is as follows:

Time planning reminder: During the entire cycle, probe preparation and genetic testing are two non-compressible waiting periods. It is advisable to confirm the laboratory's work schedule with the Hong Kong center in advance to avoid delays due to holidays or sample backlogs.

Frequently Asked Questions