Normally, sperm viability is above 60%. Therefore, a sperm viability of 40% is slightly on the low side, but not considered very serious.
Sperm viability refers to the percentage of live sperms in the total number of sperms. There are many reasons for lower sperm viability, including varicocele, lower androgen levels, and so on. If you stay up late, drink too much alcohol, have too much psychological stress or are physically weak, it can also lead to a lower sperm viability.
Low sperm viability in men can affect pregnancy. Although a sperm viability rate of 40% can lead to pregnancy, the success rate of pregnancy will be reduced. Therefore, if the sperm viability is lower than normal, you should go to the hospital. Blood tests for androgen levels or other appropriate tests should be performed to find the cause of the lower sperm viability and to treat it.
Men should also practice a good lifestyle, reduce late nights, increase physical activity, and minimize alcohol consumption. After discovering low sperm viability, you can take medication as prescribed by your doctor to help you recover your health as soon as possible.