There are many reasons for recurrent miscarriage. It is thought that the most common cause is that the embryo has the wrong number of chromosomes so it cannot grow into a healthy baby. This can result in the loss of a pregnancy.
A test known as Pre-implantation Genetic Screening or PGS detects chromosome mistakes in an embryo. Use of this technology can help embryologists select an embryo that is most likely to succeed and Bourn Hall is introducing this test as an option for some patients.
Embryos that have too few or too many chromosomes are known as aneuploid. This may be a result of an inherited genetic condition, pollutants such as tobacco, or especially by the age of one or other of the parents.
Egg age in particular is known to be an important factor, and because women are born with all the eggs they will ever have, it follows that there is a greater risk of aneuploidy in women over 35. Aneuploidy does not always result in a miscarriage; it depends on the chromosome and to what extent it is affected. For example, Downs Syndrome is caused by an extra chromosome 21.
PGS detects chromosome mistakes
Selection of the best embryo is vital to IVF success, so for some patients PGS may be advised.
Bourn Hall has recently teamed up with CooperGenomics, a global leader in reproductive genetics, to offer its patients a genetic test that will help screen embryos for chromosome irregularities.
The test can be done during the IVF cycle and involves taking a small cell sample from a 5-day embryo. This is when embryo has reached blastocyst stage and the cells have differentiated into foetal and placental lines. A selection of the placental cells are removed and tested in the CooperGenomics laboratory for abnormalities, meanwhile all of the embryos are frozen. The results are sent back to the embryologist at Bourn Hall and the normal embryos identified for subsequent transfer in a frozen embryo cycle.
CooperGenomics has an outstanding track record in PGS and performs more tests in one month than other labs do in a year.
PGS beneficial for couples that have experienced:
- Recurrent miscarriage – following a natural or IVF conception
- Repeated implantation failure
- Or where the woman is over 35