Background: Male factors contribute to approximately 50% of infertile couples. However, obvious causes remain unknown in many cases. This observational study aimed to investigate the associations of clinical and lifestyle parameters with sperm parameters. Methods: This study enrolled 41 men in infertile couples without obvious causes for male infertility from July 2023 to April 2024. Semen samples were evaluated for sperm number, motility, DNA fragmentation, and oxidative stress (OS) marker oxidation–reduction potential (ORP). Blood samples were analyzed for biochemical parameters, including advanced glycation end products (AGEs), and systemic OS marker diacron-reactive oxygen metabolites (d-ROMs). Skin-accumulated AGE levels were identified with an autofluorescence method. Lifestyle factors were assessed with a lifestyle questionnaire. Results: Most of the participants were under 40 years old and non-obese with normal clinical parameters. Multiple regression analyses revealed that body mass index, serum d-ROMs, and semen ORP levels were independently associated with decreased sperm number. Additionally, serum zinc and semen ORP levels were associated with sperm motility. Furthermore, serum zinc and high-density lipoprotein cholesterol levels were associated with sperm progressive motility and DNA fragmentation, respectively. The rest of the clinical and lifestyle factors, including skin-accumulated and serum AGE levels, were not correlated with any sperm parameters. Furthermore, serum d-ROM and semen ORP levels were not correlated with each other or any of the clinical and lifestyle factors. Conclusions: Our present study indicates that both systemic and local OS may be independently involved in sperm abnormality in healthy men without obvious causes for male infertility.

Background: Assisted reproductive therapy (ART) has been utilized as an effective therapeutic strategy for addressing infertility worldwide, and one of the key determinants of ART success is the acquisition of high-quality embryos through in vitro fertilization (IVF). We investigated which male factors were associated with embryo formation and quality in conventional IVF (cIVF). Methods: This study was an exploratory subanalysis of a trial conducted to examine the associations of clinical and lifestyle factors with sperm abnormalities in 41 men from infertile couples without identifiable male factors. From the original cohort, 21 men whose partners underwent cIVF were included for blastocyte outcome assessment. Semen samples were evaluated for standard sperm parameters and DNA fragmentation index (DFI). Blood biochemical parameters and lifestyle habits were also evaluated. Blastocysts were assessed 5 days after cIVF, and implantation success was determined 10 days after embryo transfer. Results: All participants showed normozoospermia, with mild sperm DFI in 76%. Blastocysts were formed in 32% of the oocytes following cIVF, with good blastocyst development and quality observed in 71% and 39%, respectively. The implantation success and live birth rates after embryo transfer were 53% and 43%, respectively. Regression analysis identified sperm DFI as the only variable inversely associated with all blastocyst outcomes. In contrast, no parameters were associated with implantation success or live birth rates. Conclusions: The present subanalysis suggests the hypothesis that sperm DNA fragmentation may be negatively associated with high-quality embryo formation in cIVF, even among normozoospermic men with non-severe levels of sperm DFI.

Background: Assisted reproductive therapy (ART) has been utilized as an effective therapeutic strategy for addressing infertility worldwide, and one of the key determinants of ART success is the acquisition of high-quality embryos through in vitro fertilization (IVF). We investigated here which male factors were associated with embryo formation and quality in conventional IVF (cIVF). Methods: This study was a sub-analysis of a trial conducted to examine the associations of clinical and lifestyle factors with sperm abnormalities in 42 men of infertile couples without identifiable male factor infertility. From the original cohort, 21 men whose partners underwent cIVF were included. Semen samples were evaluated for standard sperm parameters and DNA fragmentation index (DFI). Blood biochemical parameters and lifestyle habits were also evaluated. Blastocysts were assessed 5 days after cIVF, and implantation success was determined 10 days after embryo transfer. Results: Normospermia and oligospermia were observed in 67% and 33% of participants, respectively, with mild sperm DFI in 76%. Blastocysts were formed in 32% of the oocytes following cIVF. Among them, good blastocyst development and quality were observed in 71% and 39%, respectively. Eighteen women underwent blastocyst transfer, resulting in an implantation success rate of 50%. Multiple regression analysis identified sperm DFI as the only variable inversely associated with blastocyst outcomes. In contrast, only female age was associated with implantation success. Conclusions: The present findings suggest that sperm DNA fragmentation may negatively affect high-quality embryo formation in cIVF, even among normospermic and oligospermic men with non-severe sperm DFI.

Background: Assisted reproductive therapy (ART) has been utilized as an effective therapeutic strategy for addressing infertility worldwide, and one of the key determinants of ART success is the acquisition of high-quality embryos through in vitro fertilization (IVF). We investigated here which male factors were associated with embryo formation and quality in conventional IVF (cIVF). Methods: This study was an exploratory sub-analysis of a trial conducted to examine the associations of clinical and lifestyle factors with sperm abnormalities in 41 men of infertile couples without identifiable male factors. From the original cohort, 21 men whose partners underwent cIVF were included for blastocyte outcome assessment. Semen samples were evaluated for standard sperm parameters and DNA fragmentation index (DFI). Blood biochemical parameters and lifestyle habits were also evaluated. Blastocysts were assessed 5 days after cIVF, and implantation success was determined 10 days after embryo transfer. Results: All participants showed normozoospermia with mild sperm DFI in 76%. Blastocysts were formed in 32% of the oocytes following cIVF, with good blastocyst development and quality observed in 71% and 39%, respectively. The implantation success and live birth rates after embryo transfer was 53% and 43%, respectively. Regression analysis identified sperm DFI as the only variable inversely associated with all blastocyst outcomes. In contrast, no parameters were associated with implantation success or live birth rates. Conclusions: The present findings suggest the hypothesis that sperm DNA fragmentation may negatively affect high-quality embryo formation in cIVF, even among normozoospermic men with non-severe levels of sperm DFI.

Background: In Japan, where infertility treatment is now covered by insurance, appropriate protocols for patients with diminished ovarian reserve (DOR) based on treatment outcomes and cost-effectiveness must be selected. Therefore, this study aims to provide information on the outcomes and cost-effectiveness of conventional ovarian stimulation and mild stimulation for patients with DOR in Japan. Methods: Data from 66 women who underwent first oocyte retrieval at Showa University Hospital between May 2019 and November 2023 were analyzed. Results: The clomiphene citrate (CC) group used significantly fewer gonadotropins and incurred lower costs than the conventional ovarian stimulation group while achieving comparable clinical outcomes, including cumulative live birth rates. Conclusions: CC-based minimal stimulation is a cost-effective alternative to conventional ovarian stimulation for patients with low ovarian reserve without compromising clinical efficacy. Further randomized controlled trials are required to confirm these findings and optimize protocols for this population.

Background: Male factors contribute to approximately 50% of infertile couples. However, obvious causes remain unknown in many cases. This observational study aimed to investigate the associations of clinical and lifestyle parameters with sperm parameters. Materials and Methods: This study enrolled 41 men of infertile couples without obvious causes for male infertility from July 2023 to April 2024. Semen samples were evaluated for sperm number, motility, DNA fragmentation, and oxidative stress (OS) marker oxidation-reduction potential (ORP). Blood samples were analyzed for biochemical parameters, including advanced glycation end products (AGEs) and systemic OS marker diacron-reactive oxygen metabolites (d-ROMs). Skin-accumulated AGEs levels were identified with an autofluorescence method. Lifestyle factors were assessed with a lifestyle questionnaire. Results: Most of the participants were under 40 years old and non-obese with normal clinical and sperm parameters. Multiple regression analyses revealed that body mass index, serum d-ROMs, and semen ORP levels were independently associated with decreased sperm number. Additionally, serum zinc and semen ORP levels were associated with sperm motility. Furthermore, serum zinc and high-density lipoprotein-cholesterol levels were associated with sperm progressive motility and DNA fragmentation, respectively. The rest of the clinical and lifestyle factors, including skin-accumulated and serum AGE levels were not correlated with any sperm parameters. Furthermore, serum d-ROMs and semen ORP levels were not correlated with each other or any of the clinical and lifestyle factors. Conclusions: Our present study indicates that both systemic and local OS may be independently involved in sperm abnormality of healthy men without obvious causes for male infertility.