The technique involves analysing the first polar body, a small membrane-bound cellular structure that is expelled from the mature egg (oocyte) before fertilisation, and which mirrors the chromosomal status of the egg.
Dr Anna Pia Ferraretti told the 22nd annual conference of the European Society of Human Reproduction that, since the change in the Italian law in 2004, doctors were banned from discarding or freezing surplus embryos and only three embryos could be created at one time, all of which had to be transferred.
"As a consequence, a maximum of three oocytes have to be selected for insemination in order to avoid the development of more than three embryos. However, the three chosen might not be the best oocytes and, especially in women over the age of 35, there is a very high chance of choosing aneuploid oocytes oocytes where one or two chromosomes have been lost or gained and which, consequently, will develop into embryos that either fail to implant or are more likely to miscarry at a later stage," said Dr Ferraretti, who is scientific director of the Societ Italiana Studi di Medicina della Riproduzione (SISMER), in Bologna, Italy.
Dr Ferraretti and her team decided to see whether analysis of the first polar body could be a safe and effective tool for choosing viable eggs for fertilisation. Previously, no other researcher had attempted to use this technique in "real time" before insemination. "It involves a great team effort and sophisticated technology," said Dr Ferraretti.
They performed 510 egg retrievals between March 2004 and July 2005, and in 266 cases they tested the first polar body for five chromosomes among the eight that were known to be m
Contact: Emma Mason
European Society for Human Reproduction and Embryology