Researchers from the Graduate School of Medicine and Pharmaceutical Sciences for Research in Toyama, Japan recently published a study on the possible correlation between large nuclear vacuoles and male infertility. The term large was defined as a nuclear vacuole measuring at least 50% wider than the sperm head. A total of 142 samples were evaluated using microscopic magnification of 3,700 to 6,150. The average age of sample donors was 35 years.
Conclusion: Participant semen samples contained at least one sperm with a large nuclear vacuole in 94.4% of samples. The presence of sperm with large nuclear vacuole did not appear to have any impact on male fertility, but researchers are not convinced no correlation exists. According to the researchers involved with the study, there may still be a correlation in cases where a large percentage of sperm measure a large nuclear vacuole.
Source: Komiya A, Watanabe A, Kawauchi Y, Fuse H. Sperm with large nuclear vacuoles and semen quality in the evaluation of male infertility. Syst Biol Reprod Med. 2012 Oct 17.