Preimplantation Diagnosis for Aneuploidies in Patients Undergoing In-Vitro Fertilization With a Poor Prognosis: A Systematic Review and Meta-Analysis

OBJECTIVE: Patients with increased maternal age and/ or repeated IVF failures are given a guarded prognosis due to the relatively poor outcomes that occur with these groups. Different techniques have been used to help increase the chance of pregnancy including Assisted Zona Hatching and Preimplantation Genetic Diagnosis (PGD) for aneuploidies. DESIGN: Systematic review and meta-analysis of prospective, controlled trials comparing Assisted Zona Hatching and Preimplantation Genetic Diagnosis (PGD) for aneuploidies in patients undergoing in vitro fertilization with a poor prognosis due to advance maternal age and/ or repeated IVF failures. MATERIALS AND METHODS: A computerized search was conducted using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library Issue 2, 2005, the National Research Register (NRR) and the Medical Research Council’s Clinical Trials Register. The following Medical Subject Headings (MeSH) and text words were used: preimplantation genetic diagnosis, assisted zona hatching, aneuploidy, IVF failures, maternal age and controlled trial(s), randomised controlled trial(s), randomized controlled trial(s). The reference lists of all known primary studies and review articles were also examined to identify additional relevant citations. In addition, a hand search of the citation lists of relevant publications, review articles; abstracts of scientific meetings and included studies were searched for trials. For the meta-analysis, in the absence of heterogeneity, results were pooled using a fixed effect model, the relative risk and risk difference (and 95% confidence intervals). Where statistical heterogeneity was found, statistical synthesis of the results using a random effects model was undertaken. RESULTS: A total of two prospective controlled trials (RCTs) were located that evaluated the use of Preimplantation Genetic Diagnosis for aneuploidies vs. Assisted Zona Hatching for patients undergoing in vitro fertilization with a poor prognosis (Gianaroli et al., 1997; Gianaroli et al., 1999). As for the implantation rate, using the fixed effect model, pooling of the results demonstrated a statistically significant increased chance of embryo implantation in patients that underwent PGD (62/ 252) vs. Assisted Zona Hatching (58/ 470) (P 0.0001; O.R 2.32; 95% CI 1.56 3.45). As for the clinical pregnancy rate, using the fixed effect model, pooling of the results demonstrated no statistical significance between the two groups: PGD (41/ 138) vs. Assisted Zona Hatching (38/ 152) (P 0.36; O.R 1.27; 95% CI 0.76 2.13). CONCLUSION: Using preimplantation diagnosis for aneuploidies in patients undergoing in vitro fertilization with a poor prognosis due to increased maternal age and/or multiple IVF failures may increase the implantation rate and therefore reduce the numbers of embryos needed to be transferred. More trials are needed to further confirm these results. Supported by: None