Time-lapse evaluation of embryos in Non-obstructive Azoospermia (NOA): high rate of 1PN fertilization and rapid embryo development in tese compared to ejaculated sperm

Abstract

Non-obstructive azoospermia (NOA), characterized by impaired spermatogenesis, presents significant challenges in assisted reproduction. Currently, comparative data on chromosomal integrity between testicular and ejaculated sperm are limited. The purpose of the current study was to compare embryo morpho-kinetics, fertilization abnormalities, and the results of preimplantation genetic testing for aneuploidy (PGT-A) between embryos derived from ejaculated sperm and those obtained from testicular sperm in cases of NOA. Methods: This retrospective study encompassed 397 patients from two IVF centers between 2015 and 2023, with 317 patients undergoing treatment using ejaculated sperm and 80 utilizing testicular sperm obtained from NOA patients. Fertilization patterns (2PN, 1PN, ≥3PN), embryo morphokinetics (from fertilization into blasto-cyst development), and aneuploidy rates were evaluated. Logistic regression was performed to determine factors affecting aneuploidy, including male and female age, recurrent implantation failure (RIF), hormone levels, and oocyte quality. Chi-square and t-tests were used for group comparisons, and statistical significance was set at p<0.05. Results: Embryos derived from testicular sperm developed faster than those from ejaculated sperm (p<0.05). The 2PN fertilization rate was significantly lower, while the 1PN rate was higher in the testicular sperm group (10.1% vs. 16.4%, p=0.020). The rates of ≥3PN anomalies and embryo aneuploidy were similar between groups (p>0.05). Logistic regression identified male age (p=0.001), female age (p=0.007), and RIF (p=0.047) as significant predictors of aneuploidy. Conclusion: Our study identified advanced parental age and RIF as key predictors of embryo aneuploidy. PGT-A may improve outcomes, particularly in older patients or those with RIF, irrespective of sperm origin.