Genetic screening 'does not improve pregnancy rates'
Thursday, 12 Jun 2008 09:14
The technique checks the DNA of embryos
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A genetic screening technique for women having fertility treatment does not improve pregnancy rates for women aged over 35, medical professionals claim.
Guidelines from the British Fertility Society (BFS) published today say the technique, called preimplantation genetic screening (PGS), should not be offered other than in clinical trials by experienced centres.
PGS has been proposed as a way to improve the success rates of assisted conception in women aged over 35, those who have several previously unsuccessful IVF cycles and for couples who have had several miscarriages.
It assesses whether an embryo (produced by IVF) has the correct number of chromosomes in each cell, prior to re-implantation into the womb.
The BFS says it found evidence that PGS does not improve pregnancy rates or decrease miscarriage rates and that live birth rates may be significantly reduced following PGS treatment.
It remains possible, the society adds, that PGS may be of benefit under certain circumstances, but there is no evidence to support this at the moment.
As a result the BFS advises that clinicians should inform their patients there is no evidence that PGS for older women improves their likelihood of becoming pregnant and in some cases may result in a reduced chance of pregnancy.
It "urgently" calls for further research to be carried out on PGS to assess its safety and efficiency in treating a range of patients including those who have suffered repeated miscarriage or implantation failure.
Professor Richard Anderson, author of the guidelines and member of the BFS' policy and practice committee, said: "The BFS wants to ensure that all women receive the safest and most effective treatment when undergoing fertility procedures.
"Following a thorough analysis of published research, it is clear that there is currently no compelling evidence that PGS improves the clinical pregnancy rate or live birth rate or that it reduces the miscarriage rate."