The most common causes behind a couple's inability to conceive are associated with male infertility (30% of the cases) or female infertility (30% of the cases).
It is possible that the cause has a mixed origin, where the reproductive potential of both partners fails. This occurs in about 20% of the cases.
Finally, infertility in the couple can be due to unknown reasons. This type of infertility is called unexplained infertility.