By Dr Julie Lindstrom, a specialist at City Fertility Centre Brisbane
At City Fertility, we pride ourselves on offering the latest techniques to give our patients the best care and maximise their chances of falling pregnant.
We now offer state-of-the-art genetic testing called PGT-A (preimplantation genetic testing – aneuploidy) for patients interested in screening embryos before transfer and achieving a pregnancy faster, knowing they have transferred normal embryos. This is a minimally invasive technique and can improve implantation rates significantly.
Genetic testing is one of the highly advanced scientific techniques that City Fertility uses to boost your chances of falling pregnant and having a healthy baby.
A sophisticated screening process for chromosome abnormalities and genetic disorders, it has helped many IVF couples achieve pregnancy by allowing only chromosomally normal embryos to be implanted into the uterus.
Like anything in life, the embryos you create are a bit of a lottery: some people get lucky, create perfect embryos, and fall pregnant easily without complications. For others, it can be harder, and fertility assistance is required to help achieve a healthy embryo and, hopefully, a pregnancy and baby.
All our cells have 46 chromosomes in 23 pairs. We inherit 1 pair from each parent. Chromosomes carry our genes, the blueprint for creating a healthy baby/person. Females are known as 46XX, and males as 46XY.
Depending on your age, anywhere from 30% to over 90% of the embryos you create can be chromosomally abnormal with the incorrect number of chromosomes.
Who is Genetic Testing Recommended for?
Genetic testing or screening is an option that can be useful for people who have had recurrent unsuccessful IVF cycles, miscarriages or who might have a family history of a chromosomal disorder.
Abnormal chromosomes can stop an embryo from implanting in the uterine lining or result in a miscarriage or the birth of a child with a genetic condition or disabilities.
Here are my top points you should know about genetic testing of embryos:
- Genetic testing is being used more widely and offering good results and pregnancy success for many. It identifies the healthy, normal embryos to be prioritised for transfer during IVF, which can often help achieve a baby sooner with a smaller financial outlay.
- Genetic testing can detect chromosomally abnormal embryos during their development in the laboratory before they are transferred.
- There are two methods of genetic testing: Preimplantation Genetic Screening (PGS) and recently also called Preimplantation Genetic Testing – Aneuploidy (PGT-A), and Preimplantation Genetic Diagnosis (PGD).
- PGS looks at whether the embryo contains the right number of chromosomes but doesn’t diagnose specific diseases. PGD is advanced single-gene testing, looking for single-gene disorders such as cystic fibrosis.
- Embryos are biopsied when they have reached the blastocyst stage, usually between days 5 and 7 after fertilisation. These biopsied cells are then tested for the number of chromosomes present or the specific single-gene disorder of interest. The embryo is frozen/vitrified immediately after the biopsy to await the genetic results.
- Cells from the embryo’s outer shell are removed and tested – the risk of damaging an embryo is less than 1%.
- It is impossible to provide certainty that every disorder can be tested for. The main goal is first to determine whether the embryo is chromosomally balanced with the correct number of chromosomes, i.e. 23 pairs of chromosomes, including X and Y.
- Genetic testing is most suitable for patients with recurrent miscarriages, unsuccessful IVF cycles, a family history of chromosomal disorders, advanced maternal age (over 38), or for those who want to increase their chance of a successful IVF cycle.
- Genetic testing involves risks and limitations; however, they are low, and your doctor will discuss these with you.
For more information, visit our Genetic Testing page, or if you are an existing patient, please feel free to discuss this option with your clinical or embryology teams.
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