As mentioned, there are multiple causes to explain the origin of infertility and there are several types of classification depending on the approach to these causes. Primary and secondary infertility Primary infertility: When the couple has not achieved pregnancy or has achieved a gestation that has not reached full term with a live newborn. Secondary infertility: when after having one or more children, the couple does not achieve a new full-term pregnancy with a live newborn. The different infertility problems can also be classified on the basis of the following criteria: Defective gamete production: The problems that will lead to infertility can originate in any of the phases of spermatogenesis (formation of spermatozoa) and ovogenesis (formation of eggs). Obstruction of the reproductive tract Inflammation or immune dysfunction Sexual disturbances