DefinitionPrimary infertility describes couples who have never been able to become pregnant after at least 1 year of unprotected sex (intercourse).Secondary infertility describes couples who have been pregnant at least once, but have not been able to become pregnant again.Alternative NamesInability to conceive; Unable to get pregnantCauses, incidence, and risk factorsCauses of infertility include a wide range of both physical and emotional factors. A couple's infertility may be due to female factors, male factors, or both:FEMALE INFERTILITY:Female infertility may be due to:Problems with a fertilized egg or embryo being able to survive once it is attached to the lining of the uterusProblems with the fertilized egg being able to attach to the lining of the uterusProblems with the eggs being