Risky and unnecessary embryo genetic testing (PGT-A) in Malaysia is driven by culture

Angelica Cheng

Active Member

Risky and unnecessary embryo genetic testing (PGT-A) in Malaysia is driven by culture

Currently in Malaysia, many fertility clinics strongly encourage and even push their patients to do highly expensive preimplantation genetic testing of their IVF embryos, technically referred to as PGT-A or PGS.

It is widely claimed that this technique not only prevent birth defects in older women such as Down syndrome, but also enhances IVF success rates by weeding out non-viable genetically-defective embryos that occur frequently in older women. Additionally, because PGT-A inevitably reveals the sex of IVF embryos through identification of sex (X and Y) chromosomes, patients can also discreetly do sex selection of their IVF embryos on the sidelines, besides checking for genetic defects and avoiding abortion.

Various sociocultural factors in Malaysia would favour the uptake of PGT-A in IVF treatment.

First, there is no legal clarity on whether fetuses that are diagnosed to be abnormal by prenatal testing (e.g. Down Syndrome) can lawfully be aborted. To put it simply, termination of pregnancy is mostly illegal under Sections 312 to 316 of the Malaysian Penal Code, which specify that abortion is permitted only if continuation of pregnancy increases risk to the mother’s life, or if it causes injury to the mother’s physical or mental health greater than if the pregnancy were terminated. The law does not exactly specify diagnosis of congenital defects in fetuses. Consequently, abortion is not readily available in Malaysia. Public government-funded medical facilities usually do not offer abortion services, which are available only at high costs in private hospitals.

Second, abortion is unanimously considered to be immoral by all major religious faiths in Malaysia and a large fraction of the country’s population hold strong religious beliefs, which would make patients want to avoid the abortion of defective fetuses as much as possible, so not to offend their own religious beliefs and hurt their personal conscience.

Third, congenital defects such as Down syndrome are heavily stigmatized in Malaysian culture and there are limited facilities catering to the care and education of disabled children in the country.

Fourth, a new generation of educated women are increasingly aware that the rising age of motherhood in Malaysia is associated with elevated risks of genetic defects such as Down syndrome.

Finally, drastic reduction of family sizes in Malaysia over the past few decades would incentivise prospective parents to invest more heavily in their fewer children, including doing expensive genetic testing in IVF treatment.

The high price of PGT-A often increases the total medical fees by 20% to 30%. Hence, it is necessary to highlight what patients should know about the risks and necessity of doing the procedure, before deciding to add this to their already-expensive IVF treatment cycle.

First and foremost, patients should be informed that the latest scientific and clinical data cast doubt on the widely-claimed benefits of embryo genetic testing in improving IVF success rates. Large-scale clinical trials involving hundreds of patients receiving treatment at multiple IVF centres in several countries have demonstrated conclusively that embryo genetic testing (PGT-A) does not significantly improve IVF success rates. These include the ESTEEM trial (2018) and STAR trial (2019) conducted in Western countries, as well as a 2021 China-based clinical study published in the New England Journal of Medicine.

More recently, retrospective analysis of 133,494 IVF cycles recorded within the SART (Society for Assisted Reproductive Technology) Clinical Outcome Reporting System database, found that application of PGT-A in all patients with late-stage embryos (blastocysts) available for transfer or screening was in fact associated with a lower cumulative live birth rate than routine IVF. This negative association of PGT-A with cumulative live birth rate was especially pronounced in patients below 35 years old, even though this was not observed in those aged 40 years and above.

Second, patients should understand that PGT-A is a highly invasive technique that involves extracting cells from embryos for genetic testing (biopsy), which is potentially harmful, and can impair its development. Many experts have pointed out that studies claiming no ill-effects on embryos are often based on testing of excellent quality, healthy, robust embryos rather than more delicate lower-quality embryos that might suffer more. Because older women tend to have fewer lower-quality embryos, they are at higher risks of embryo damage from genetic testing.

Third, patients should be told that genetic testing involves extracting and sampling cells from the outer embryo layer (trophectodem) that gives rise to the placenta and umbilical cord. This is not representative of the inner embryo layer (Inner Cell Mass) that goes on to form the actual fetus, which gives rise to the baby. Mosaic embryos, which are embryos with a mixture of genetically normal and abnormal cells occur quite frequently and commonly among woman undergoing IVF. Genetic testing often leads to the misdiagnosis and discarding of mosaic embryos, which have been shown to be capable of giving rise to a normal and healthy baby.

Finally, there is scientific evidence that mosaic embryos are able to “self-correct”, which increases the chances of normal birth. This “self-correction” mechanism involves pushing out the genetically abnormal cells into the outer embryo layer, which gives rise to the placenta and umbilical cord. Older women tend to have much fewer embryos during IVF. Therefore excluding or discarding of mosaic embryos that can potentially give rise to a normal baby, would in fact substantially reduce their chances of IVF success. Some older women may have no embryos left to transfer after genetic testing.

Hence, due to increasing doubts on the therapeutic benefits of PGT-A, patients should therefore think twice before choosing to add on this highly expensive technique to their IVF treatment, which potentially risks damaging their embryos. Perhaps it should be made compulsory for IVF patients to receive counselling by a certified genetic counselor to better understand the risks and necessity of doing the procedure.