Preimplantation genetic screening reduces successful pregnancies after IVF

Preimplantation genetic screening of embryos for chromosome abnormalities reduces the success rate of in vitro fertilisation (IVF) by nearly a third in older women, according to a European study (New England Journal of Medicine 2007;356:9-17).

The study looked at the rates of ongoing pregnancies and live births in a total of 408 women aged 35 to 41 years undergoing a total of 862 cycles of in vitro fertilisation. Half of the women (206) were randomised to undergo preimplantation genetic screening, and the other half were a control group and were not screened. Screening involved taking a biopsy of one cell at three days and testing chromosomes to detect trisomies or other abnormalities in chromosome number.

Sebastiaan Mastenbroek, from the Center for Reproductive Medicine at the University of Amsterdam, the Netherlands, and lead author of the study, explained the rationale, “Pregnancy rates in women of advanced maternal age undergoing IVF are disappointingly low. A potential cause is the increased incidence of chromosomal abnormalities. It has been suggested that use of preimplantation screening of cleavage stage embryos for aneuploidies may improve the effectiveness of …