Preimplantation Genetic Testing for Aneuploidy in In Vitro Fertilization Using Comprehensive Chromosome Screening: A Systematic Review and Meta-Analysis

Abstract

The utility of pre-implantation genetic testing (PGT-A) is controversial, with older meta-analyses demonstrating improvedpregnancy outcomes, while newer trials have not shown benefit. Therefore, we performed a meta-analysiswhich aimed to evaluate the benefits of PGT-A using comprehensive chromosome screening (CCS) and its effects onin vitro fertilization (IVF) outcomes among randomized controlled trials (RCTs). We conducted a systematic searchto identify RCTs comparing women undergoing PGT-A with CSS with women not undergoing PGT-A, from inceptionto December 2020. Random effects meta-analysis was utilized to calculate average odds ratios (OR) for clinicalpregnancy rate (CPR), ongoing pregnancy rate (OPR), and miscarriage rate (MR). The heterogeneity of exposure wasassessed using Forest plots and I2 statistics. Publication bias was evaluated using Egger’s test. Among 1251 citations,seven RCTs met the inclusion criteria. Biopsies of embryos were carried out at various developmental stages, includingpolar body, day 3, and day 5-6 of culture. Data was analyzed as all studies and blastocyst only. Meta-analysis failedto show improvement in OPRs using PGT-A in the all ages, <35 years old and ≥35 years old age groups. There wasalso no significant difference in CPRs in any group. The MR decreased with the use of PGT-A (among all biopsy typesand among blastocyst biopsies) in the all-ages group, but not when stratifying according to patient age <35 and ≥35years old. More data regarding the risks and advantages of PGT-A are needed to make a final decision on the valueof this intervention in clinical practice. The exact magnitude of the benefit of PGT-A selection cannot be correctlydetermined until multiple standardized protocol IVF PGT-A trials are conducted.

Keywords

• in vitro fertilization
• meta-analysis
• preimplantation genetic screening