P-057 Do the reduction of sexual abstinence influence sperm DNA fragmentation? Exploring the relationship between the two parameters
Authors: Castellano S , Carnesi E , Albani E , Bulbul O , Smeraldi A , Levi Setti P  E 
Published: July 2024

Abstract

Study question
Is the reduction of sexual abstinence (SA) really beneficial on sperm DNA fragmentation?

Summary answer
Despite recent studies support short SA’s positive impact on sperm parameters, apparently a reduced SA has not a clear impact on sperm DNA fragmentation.

What is known already
Sperm DNA fragmentation (sDF) has been linked to male infertility, affecting the success of fertility treatments. It’s strictly associated with failure and/or no longer time to conceive, impaired embryo development or higher miscarriege rates. The exact mechanism for age-dependent patterns of sperm decline is still not fully understood. Several factors, such as the increase in free radicals in conjuction with the rising in SA, have been discussed in literature. Recent studies support short SA’s positive impact on sperm parameters, despite controversial results; hence, we decided to analyze the trend in our facility: Humanitas Fertility Center.

Study design, size, duration
The present retrospective analysis, performed between 2021 and 2023, aims to investigate whether or not a reduced SA is beneficial on sperm DNA fragmentation in patients undergoing IVF. In our study 828 patients (from 21 to 59 years old) underwent both sperm analysis and sDF evaluation through Sperm Chromatin Structure Assay (SCSA). A DNA fragmentation index (DFI) lower than 30% indicates a sperm population with a good chromatin integrity, according to current knowledge.

Participants/materials, setting, methods
Patients were split in 4 groups, based on their age (≤38 and &gt;38 years) and days of SA (0-3 and 4-7 days). Group 1 (n = 111/828): ≤38 years, ≤3 days; Group 2 (n = 359/828): ≤38 years, &gt;3 days; Group 3 (n = 83/828): &gt;38 years, ≤3 days; Group 4 (n = 275/828): &gt;38 years, &gt;3 days. Statistics was performed to analyze the variance among DFI values belonging to the four groups analyzed.

Main results and the role of chance
The results are expressed as mean(±SD). In Group 1, DFI %: 22,5(±14,7); in Group 2, DFI %: 21,5(±14,3); in Group 3, DFI %: 22,3(±14,9); in Group 4, DFI %: 26(±16,3). Surprisingly we observed the same behavior between most of the groups analyzed, except for the one belonging to the older patients. As a matter of fact, we found no statistical difference by comparing the DFI values belonging to samples of the same age stratification (≤38 or &gt; 38 years), indeed Group 1 vs. Group 2: P=0,546; Group 3 vs. Group 4: P=0,1152. Different results were observed by comparing groups with the same SA days (≤3 or &gt; 3), but belonging to a different age stratification, as it follows: Group 1 vs. Group 3: P=0,6384; Group 2 vs. Group 4: P=0,0001. This leads us to think that only the mixture of advanced paternal age (&gt;38 years) and the increase of SA defines a worsening of DFI, according to our patients’ stratification.

Limitations, reasons for caution
There’s no homogeneity in the number of patients recruited with ≤3 days of SA compared to those with &gt;3 days, as expected. Men undergoing fertility treatments follow strict SA guidelines; moreover, there’s no consensus about to request a second semen sample in clinical practice, in order to eliminate SA.

Wider implications of the findings
Exploring the inclusion of a broader spectrum of patients with low SA, despite their age, or instructing them to undergo semen analysis with a 0-day SA, could yield interesting insights. This could lead to targeted interventions and treatments, offering further hope for individuals with sDF issues.

Trial registration number
Not applicable