Normal conception will occur for three out of five fertile couples within six months of attempting to conceive. One out of four fertile couples will successfully conceive between six months and a year. If a couple is unable to conceive after a full year of attempting to become pregnant, they are considered infertile. Infertility is defined as the lack of conception after twelve months of unprotected intercourse.
Infertility can occur at any time throughout a person's sexual lifetime.
Individuals who have previously conceived and successfully given birth may experience infertility problems with subsequent attempts. Both males and females are equally likely to be infertile. If, however, after three years of infertility treatment, a couple continues to be unsuccessful in conceiving, they are considered sterile. Sterility is defined as the presence of a condition in one or both partners when a cure or treatment in either unsuccessful or unavailable. It is important to realize that infertility and sterility, although related, are by no means the same.