Minister for Health Gan Kim Yong has announced that the Government has granted approval on Pre-Implantation Genetic Screening (PGS) to identify chromosomal abnormalities in embryos created through in-vitro fertilization (IVF), with the aim of improving the chances of conceiving.
This is the response on MP for Nee Soon GRC Mr Louis Ng Kok Kwang’s queries who asked the Minister for Health considering that gender bias for Pre-Implantation Genetic Screening (PGS) can now be blinded, whether the Ministry will consider permitting women with recurrent miscarriages or a history of infertility to seek PGS in Singapore.
The MP for Tampines GRC Miss Cheng Li Hui also asked questions on whether the Ministry will consider permitting Pre-Implantation Genetic Screening to improve the chances of healthy live births, subject to strict controls such as banning sex selection and use for other non-medical reasons.
The Minister said that MOH had previously received requests to allow PGS. However, it had not granted approval so far as the published evidence had been unclear.
He stated that in recent years however, newer technologies for PGS have emerged and some jurisdictions have now allowed PGS.
Therefore, MOH is reviewing the clinical effectiveness of PGS and its ethical implications. The National University Hospital (NUH) will be conducting a three-year pilot PGS programme which will commence by early next year to assess clinical effectiveness.
The Minister stressed that MOH will also look into the ethical concerns and regulation of PGS. For example, we will need to ensure that embryos are not eliminated solely based on parental preferences on characteristics such as gender.
“MOH will consult stakeholders and the public to gather views,” it wrote.
A lot of Singaporean women had to go overseas to do the PGS as it is not available in the country.
It is performed as part of the IVF process. For all couples the following steps will be performed:
- Female partner takes medications to stimulate the ovaries to make multiple eggs grow
- Eggs are retrieved with a transvaginal needle in an office procedure
- Eggs are fertilized by sperm using a process called ICSI
- Embryos develop in the embryology laboratory over the course of 5-6 days
On day 5 or 6 of development, when embryos have reached the blastocyst stage, a few cells that would eventually become placental cells are removed from the outer layer of the embryo (this is called a trophectoderm biopsy). The cells are then sent to a special laboratory that will test for chromosomal abnormalities in the embryo using the most advanced techniques.
The embryos are frozen immediately, using vitrification. When the results are returned, chromosomally normal embryos can be thawed and placed back in the uterus in a subsequent frozen embryo cycle.
Of the embryo(s) that are chromosomally normal, the best quality embryo(s) are selected for transfer to the uterus. If additional chromosomally normal embryos are available, they may remain cryopreserved for a future embryo transfer.