Preimplantation genetic screening in advanced maternal age: a systematic review

Advanced maternal age (AMA) is associated with high rates of aneuploidy, which leads to early pregnancy loss and high failure rates of assisted reproductive technology (ART). It has been hypothesized that preimplantation genetic screening, which analyzes embryos for aneuploidies prior to implantation, would increase implantation, reduce miscarriages and enhance live birth rates in women of AMA. Preimplantation genetic screening is currently being used clinically, despite inconclusive evidence of its efficacy. The objective of this article is to evaluate the clinical effectiveness of preimplantation genetic screening in terms of live births in women of AMA undergoing ART. The Cochrane Central Register of Controlled Trials (issue 2, 2009), MEDLINE (1978–2010) and EMBASE (1980–2010; all searched June 2010) were searched for relevant randomized controlled trials. Reference lists of included studies were searched and authors were contacted in cases where further data were required. Six randomized controlled trials fulfilled our predetermined inclusion criteria. The live birth rate (odds ratio; 95% CI) per woman was found to be significantly lower in the preimplantation genetic screening group (0.48; 0.26–0.88). There was a wide difference in the methodology of the preimplantation genetic screening across the studies. There is not enough evidence to condone routine clinical use of preimplantation genetic screening with existing techniques in women of AMA undergoing ART. Comparative genomic hybridization and microarray technology should be explored, and alternative culture conditions and timings for biopsy should be evaluated in future trials using standardized methodology to allow definitive conclusions of its clinical effectiveness to be derived.