Other treatment options
Embryo screening
With fewer and fewer embryos now replaced in each transfer cycle of IVF, embryo selection has become more important than ever. Traditionally, embryos are chosen according to their appearance under the microscope after three or five days of development in the incubator. However, in the past few years additional techniques of selection have been introduced which use high-tech methods to screen embryos for genetic and chromosomal information. Some studies have shown that as many as 50% of embryos are chromosomally abnormal, and, if transferred, such embryos may fail to implant in the uterus or later miscarry. The risk of chromosomal abnormalities - such as Down's syndrome - increases with maternal age.
The London Women's Clinic has begun to use new techniques of embryo analysis which indicate the chromosomal health of each embryo. The idea is that only good-looking embryos without chromosome abnormalities are transferred, thus reducing the risk of pregnancy failure.
PGD
The technique of preimplantation genetic diagnosis (PGD) can be performed successfully in couples who are known to be at risk of passing on an inherited genetic disease to their children; however, this is a complex and demanding treatment, and appropriate only for couples known to be carriers of a genetic mutation.
It's fair to say that PGD has revolutionised the prospects of parenthood for couples who are known carriers, for example, the cystic fibrosis gene mutation. By identifying and transferring those embryos without the mutation, carrier couples can be reassured that their baby will not be affected.
However, the application of the same technology as a screening measure (preimplantation genetic screening, PGS) requires a number of embryos created by IVF or ICSI and mainly screens for chromosomal abnormalities such as Down's syndrome.
CGH
The technique of comparative genomic hybridization (CGH) is when a cell from the developing embryo has all of its chromosomes screened for additions, omissions and abnormal forms. This test can be useful for looking for Down's syndrome (which is usually as a result of there being three instead of two of chromosome 21) and other chromosome abnormalities. CGH is still experimental and is being tested in a clinical trial at the LWC. Please get in touch to find out more about the trial and how you can get involved.
