(267) Flow Cytometry Sperm Apoptosis Test Can Predict Sperm DNA Fragmentation and Can Be Used as an Effective and Easy-To-Perform Screening Method for Males from Infertile Couples

Introduction Conventional sperm analysis is the gold standard for male fertility assessment. However, since the basic examination consists of microscopic evaluation of native ejaculate, some sperm pathologies might be missed during this examination. The sperm DNA fragmentation (SDF) test is currently considered the most precise indicator of the sperm potential to fertilize an oocyte both naturally and by assisted reproductive technologies. Irrespective of which method is used, sperm DNA fragmentation testing requires special technical equipment and chemicals together with skilled laboratory staff, and is usually time-consuming and costly. Objective In our IVF centre, we introduced flow cytometry sperm apoptosis test as a simple and inexpensive screening method to select patients who may benefit from subsequent SDF test, which is currently not covered by the public health care insurance in our country. Methods We analysed data from 688 men (age 19-66 years, mean 30,1 years, standard deviation 10,8 years), who, in the period from I/2019 to XII/2024, underwent 971 TUNEL SDF tests performed together with flow cytometry sperm apoptosis test and conventional sperm analysis. Correlation between continuous variables was computed using the non-parametric Spearman correlation coefficient. Differences in continuous variables among groups were assessed by the non-parametric Kruskal-Wallis test. The Kruskal-Wallis test compared the medians of the samples in the groups and returned a p-value for the null hypothesis that all samples are drawn from populations with the same distribution. The Kruskal-Wallis test is a non-parametric version of the classical one-way ANOVA, and an extension of the Wilcoxon rank sum test for more than two groups. For prediction of the SDF, a standard linear regression model was used. All tests were performed at the 0,05 level of significance. The statistical analysis and data visualisation were performed using MATLAB and Statistics Toolbox Release 7.5.0.342 (R2007b), The MathWorks, Inc., Natick, Massachusetts, US. Results A significant correlation was found between the percentage of SDF and the percentage of late apoptotic/necrotic sperm (c=0,38, p<0,001), and a significant negative correlation was found between the percentage of SDF and the percentage of viable sperm (c=-0,39, p<0,001) (Figs. 1 and 2, respectively). The correlation between the percentage of SDF and the percentage of early apoptotic sperm was less significant (c=0,10, p=0,002). Among conventional sperm analysis parameters, a significant correlation between total sperm count and SDF was observed (p<0,001). A simple linear model for calculation of SDF: SDF [%] = 23 + 0,32 × age [years] – 0,35 × viable sperm [%] together with a nomogram (Fig. 3; the blue numbers above the lines indicate the predicted percentage of SDF) were created. Based on this model, males in higher risk of having high levels of SDF might be selected, which ultimately may save substantial time and financial resources. Conclusions The flow cytometry apoptosis test is an inexpensive, accurate, and easy-to-perform method and might be used effectively as a screening tool to select males in higher risk of having high levels of SDF. Disclosure No