AZFc microdeletions and outcomes of Assisted Reproduction Technology: A systematic review and meta-analysis

Existing evidence on the effect of AZFc microdeletions on sperm retrieval and ART outcomes is limited and conflicting in nature OBJECTIVE: To investigate if AZFc microdeletions affect Assisted Reproductive Technology (ART) outcomes DATA SOURCES: Electronic databases were searched for studies investigating the association of AZFc microdeletions and ART outcomes from inception to April 2023 STUDY SELECTION AND SYNTHESIS: Case-control studies were analyzed. Study population included infertile men with and without AZFc microdeletions. Study quality was assessed using the Newcastle-Ottawa Scale. Summary effect sizes (odds ratio [OR] with 95% confidence interval [CI]) were calculated for both categories of men.The primary outcome was successful sperm retrieval and the secondary outcomes were outcomes of ART.(S): Case-control studies reporting sperm retrieval rates and ART outcomes in men with AZFa and AZFb deletions were unavailable. Based on data of 3807 men, sperm retrieval rates were found to be higher in men with AZFc microdeletions as compared to their non-deleted counterparts [OR = 1.82, 95% CI 0.97, 3.41] but the difference was not statistically significant (P = 0.06). A significantly lower fertilization rate (OR = 0.61, 95% CI 0.50, 0.74), clinical pregnancy rate (OR = 0.61, 95% CI 0.42, 0.89) and live birth rate (OR = 0.54, 95% CI 0.40, 0.72) was observed in men having AZFc deletions as compared to men without deletions. There was no statistically significant difference in rates of embryo cleavage, blastocyst formation, good quality embryos, implantation and miscarriage between the two groups. On correcting for female factors, the fertilization rate (OR = 0.76, 95% CI 0.71, 0.82), cleavage rate (OR = 0.54, 95% CI 0.41, 0.72), clinical pregnancy rate (OR = 0.39, 95% CI 0.30, 0.52) and live birth rate (OR = 0.48, 95% CI 0.35, 0.65) were significantly lower in men with AZFc deletions as compared to controls.(S) AND RELEVANCE: AZFc microdeletions are significantly associated with adverse outcomes in ART. Further studies are required to accurately elucidate the effect of AZFc microdeletions on ART outcomes.