Embryo screening for IVF discouraged

Embryo chromosome screening should not be offered to women to improve their chances of getting pregnant through in-vitro fertilisation, according to the British Fertility Society (BFS). Preimplantation genetic screening (PGS) is used to assess which embryos are most likely to come to term in women aged over 35 who are undergoing IVF, and those who have suffered IVF failures or repeated miscarriages. The technique takes a single cell from the multiple embryos created outside the body and checks it for genetic abnormalities called aneuploidies, which involve missing or an extra pair of chromosomes.

If the embryo is found to have them, it is not implanted into the woman, as it is thought that an embryo with these abnormalities may fail to implant or grow correctly.

But new guidelines from the BFS say that there is no evidence that PGS improves the chance of success or cuts the risk of miscarriage.

Professor Richard Anderson, who wrote the guidelines, said: "Following a thorough analysis of the 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.

"There is now an urgent need for further research on PGS to assess both its safety and efficiency in treating a range of patients."

Less than 200 women in the UK undergo the procedure each year.

It is an expensive procedure and adds more than £1,000 to every cycle of IVF.