In males, either disorder is caused by impotence, the inability to achieve an erection, and a decrease in sperm count. In females, the common causes include disorder of the Fallopian tubes, loss of ovulation, and mucus secretions from the cervix that kill off sperms.

Males can improve the quality of their sperm by avoiding alcohol, smoking, and caffeine and having a proper diet and enough sleep and exercise. For females, doctors usually recommend a medicine to improve ovulation.