in approximately 5% to 10% of couples trying to conceive, all of the above tests are normal and there is no apparent cause for infertility.
In a much higher percentage of couples, only minor abnormalities are found that are not severe enough to result in infertility.
In these cases, the infertility is referred to as unexplained.
Couples with unexplained infertility may have problems with egg quality, tubal function, or sperm function that are difficult to diagnose and/or treat.
Fertility drugs and IUI have been used in couples with unexplained infertility with some success.
If no pregnancy occurs within three to six treatment cycles, IVF may be recommended.