A couple is visiting the clinic because they have been unable to conceive a baby after 3 years of frequent coitus. the nurse determines that the couple needs further instruction when they identify which factor as a cause of male infertility?

It is possible that the male sperm cells are not healthy ie they cannot swim towards the egg or they die before they need to swim so if this is the case then of course they would be unable to fertilize the egg and it may be necessary to introduce some healthy sperm from elsewhere ie by invitro fertilization?