In Malaysia, many IVF clinics actively promote – and even pressure patients to undergo – costly preimplantation genetic testing for aneuploidy (PGT-A). These clinics claim that PGT-A not only reduces the risk of conditions such as Down's syndrome, but also improves IVF success rates by eliminating genetically abnormal embryos.
Conversely, the UK Human Fertilisation and Embryology Authority has assigned a 'red' rating to PGT-A, reflecting concerns about the lack of conclusive evidence supporting its role in enhancing conception rates and the potential reduction in the number of embryos available for transfer.
Moreover, PGT-A inevitably identifies the X and Y chromosomes, allowing patients to covertly select the sex of their embryos, in addition to screening for genetic abnormalities. Officially, the Malaysian Medical Association (MMA) prohibits non-medical sex selection of IVF embryos, but preventing Down's syndrome is often used as a convenient excuse and pretext.
Sociocultural factors
A multitude of sociocultural factors in Malaysia underpins the increasing application of PGT-A in IVF cycles.
First, many expectant mothers are concerned about the lack of legal clarity regarding the abortion of fetuses diagnosed with abnormalities through prenatal testing. Sections 312 to 316 of the Malaysian Penal Code permits abortion only in cases where the continuation of the pregnancy poses a risk to the mother's life or results in greater physical or mental harm to her than if the pregnancy were terminated. The law does not specifically address congenital defects in fetuses, which contributes to the limited availability of abortion services in Malaysia. Publicly funded medical institutions typically do not offer abortion services, which are instead available at considerable expense in private hospitals.
Second, the prevailing view among all major religious faiths in Malaysia is that abortion is immoral, and a large portion of the population adheres to strong religious beliefs. This cultural backdrop can lead patients to avoid the abortion of genetically-abnormal fetuses to remain faithful to their religious convictions and to safeguard their personal conscience.
Third, congenital defects, and genetic conditions such as Down's syndrome, are heavily stigmatised in Malaysian society. As such, there are limited facilities available that provide care and education for disabled children.
Fourth, the younger generation of educated women is increasingly aware that advancing maternal age is associated with a greater risk of genetic defects and genetic conditions.
Last, the decrease in family sizes in Malaysia over recent decades encourages prospective parents to invest more in fewer children, which may include expensive genetic testing as part of IVF treatments.
What patients need to know
The cost of PGT-A can often increase the total cost of IVF treatment by 20 to 30 percent. Consequently, it is crucial to inform patients about the financial risks and the necessity of these tests in advance.
Recent scientific and clinical findings challenge prevalent assertions on the benefits of PGT-A in improving IVF success rates. Clinical trials involving hundreds of patients across multiple clinics in different countries, have conclusively shown that PGT-A does not significantly enhance IVF success rates. Key studies include the 2018 ESTEEM trial (see BioNews 962) and the 2019 STAR trial, both conducted in Western countries, along with a 2021 clinical study from China (see BioNews 1123).
An analysis of 133,494 IVF cycles in the Society for Assisted Reproductive Technology Clinical Outcome Reporting System database indicated that implementation of PGT-A in patients with late-stage embryos (blastocysts) available for transfer or screening is linked to a reduced cumulative live birth rate relative to conventional IVF. This negative correlation was notably more pronounced in individuals younger than 35 years, while no similar effect was observed in patients aged over 40.
Patients must also understand that PGT-A is an invasive technique that involves biopsy of embryos to extract cells for genetic testing. This procedure is potentially harmful and may disrupt normal development of the embryos. Experts have pointed out that studies that indicate no adverse effects on embryos are often based on high-quality, healthy embryos, rather than the more delicate lower-quality embryos that are more prone to damage.
Moreover, older women are likely to have fewer, lower-quality embryos, thereby increasing their risk of experiencing embryo damage as a consequence of genetic testing.
Patients should be informed that genetic testing requires the extraction and sampling of cells from the trophectoderm, the outer layer of the embryo that contributes to the formation of the placenta and umbilical cord. This process does not directly provide information about the cells that will develop into the fetus, and eventually, the baby. Importantly, mosaic embryos, which contain a mix of genetically normal and abnormal cells, are frequently observed in women undergoing IVF. Genetic testing may lead to discarding these embryos, which research indicates can still result in the birth of a healthy child (see BioNews 1122).
Scientific evidence supports the notion that mosaic embryos can engage in a 'self-correction' process that increases the probability of a normal birth by shifting abnormal cells to the trophectoderm (see BioNews 1097). This is relevant because older women often produce fewer embryos during an IVF cycle, therefore, discarding mosaic embryos can lower their chances of a live birth. Some women may end up with no embryos available for transfer.
Finally, there are ongoing class action lawsuits involving PGT-A in the USA (see BioNews 1261), where plaintiffs are seeking financial compensation and punitive damages for loss of parenthood chances and emotional distress caused by discarding viable mosaic embryos misdiagnosed by PGT-A. It is alleged that several genetic testing companies have misled patients to take up PGT-A by deceptive advertising and withholding of relevant information on its limitations. A recently concluded lawsuit in Australia that led to an A$56 million payout to 700 patients, underscores the devastating consequences of flawed genetic testing practices in IVF.
In light of the increasing uncertainty surrounding the therapeutic benefits of PGT-A, patients should deliberate thoroughly before opting to include this expensive technique in their IVF cycle as it could potentially jeopardise their chances of conception. It may be prudent to require IVF patients to consult with a certified genetic counsellor to enhance their understanding of the risks involved and the justification for adding PGT-A to their IVF treatments.
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