Sperm vacuoles negatively affect outcomes in intracytoplasmic morphologically selected sperm injection in terms of pregnancy, implantation, and live-birth rates

Objective To retrospectively evaluate whether sperm vacuoles influence clinical results, with a particular focus on live-birth rates, in 101 intracytoplasmic morphologically selected sperm injection (IMSI) cycles. Design Retrospective, observational study. Setting Medical center. Patient(s) A total of 101 couples with at least two failed intracytoplasmic sperm injection (ICSI) attempts and impaired sperm morphology. Intervention(s) Patients divided into two groups according to sperm morphology and vacuolization pattern: group A comprising patients with good quality spermatozoa (type I and/or type II spermatozoa) (n = 63 patients); group B comprising patients with low quality spermatozoa (type III and/or IV spermatozoa) (n = 38 patients). Main Outcome Measure(s) Fertilization rate, embryo quality, pregnancy, implantation, and live-birth rates. Result(s) No statistically significant differences were observed between group A and B with regard to "early" assisted reproduction outcomes (fertilization rate and embryo quality). However, the "late" outcomes (pregnancy, implantation, and live-birth rates) were statistically significantly higher in group A. Conclusion(s) These results confirm a correlation between sperm vacuoles and a negative IMSI outcome, suggesting that sperm vacuoles are related to the late paternal effect.