Sperm organelle morphologic abnormalities: contributing factors and effects on ICSI outcomes

Abstract

OBJECTIVE: The goals for this study were to: (i) analyze possible relationships between motile sperm organelle morphology and sperm chromatine status, aneuploidy incidence and patient's age and (ii) determine the effects of sperm morphological abnormalities on intracytoplasmic sperm injection (ICSI) cycles outcomes.DESIGN: Prospective trial.MATERIALS AND METHODS: The study was performed in 50 patients undergoing ICSI cycles. The motile sperm organelle morphology examination (MSOME), sperm DNA fragmentation and sperm aneuploidy incidence were performed in 200 sperm cells of each patient. Regression models were used to assess the relationships between sperm morphology and sperm aneuploidy, sperm DNA fragmentation, patient's age and ICSI outcomes.RESULTS: A close relationship between sperm DNA fragmentation and the presence of vacuoles in the MSOME (R2: 0.067, P = 0.029 for large vacuole and R2: 0.063, P = 0.034 for small vacuoles) was noted. Patient's age was also correlated to the presence of vacuoles (R2: 0.118, P<0.001, for large vacuole and R2: 0.104, P<0.001 for small vacuole). On the other side, no correlation between sperm aneuploidy and sperm morphology was observed. The percentage of normal cells in the MSOME was determinant to the likelihood of fertilization (R2: 0.040, P =0.054), pregnancy (OR: 1.15, P=0.046) and implantation rates (R2: 0.168, P <0.001). When the defects were evaluated individually, it was noted that vacuolated cells was negatively correlated with fertilization, pregnancy and implantation.CONCLUSION: Our data suggest that the selection of sperm for intracytoplasmic injection based on the normal nuclear morphology may be a useful tool to select spermatozoa with intact DNA but not with euploid constitution. Our evidences also suggest a correlation between paternal age and incidence of nuclear vacuoles, as well as an effect of large and small vacuoles on early and late embryo development. OBJECTIVE: The goals for this study were to: (i) analyze possible relationships between motile sperm organelle morphology and sperm chromatine status, aneuploidy incidence and patient's age and (ii) determine the effects of sperm morphological abnormalities on intracytoplasmic sperm injection (ICSI) cycles outcomes. DESIGN: Prospective trial. MATERIALS AND METHODS: The study was performed in 50 patients undergoing ICSI cycles. The motile sperm organelle morphology examination (MSOME), sperm DNA fragmentation and sperm aneuploidy incidence were performed in 200 sperm cells of each patient. Regression models were used to assess the relationships between sperm morphology and sperm aneuploidy, sperm DNA fragmentation, patient's age and ICSI outcomes. RESULTS: A close relationship between sperm DNA fragmentation and the presence of vacuoles in the MSOME (R2: 0.067, P = 0.029 for large vacuole and R2: 0.063, P = 0.034 for small vacuoles) was noted. Patient's age was also correlated to the presence of vacuoles (R2: 0.118, P<0.001, for large vacuole and R2: 0.104, P<0.001 for small vacuole). On the other side, no correlation between sperm aneuploidy and sperm morphology was observed. The percentage of normal cells in the MSOME was determinant to the likelihood of fertilization (R2: 0.040, P =0.054), pregnancy (OR: 1.15, P=0.046) and implantation rates (R2: 0.168, P <0.001). When the defects were evaluated individually, it was noted that vacuolated cells was negatively correlated with fertilization, pregnancy and implantation. CONCLUSION: Our data suggest that the selection of sperm for intracytoplasmic injection based on the normal nuclear morphology may be a useful tool to select spermatozoa with intact DNA but not with euploid constitution. Our evidences also suggest a correlation between paternal age and incidence of nuclear vacuoles, as well as an effect of large and small vacuoles on early and late embryo development.