How is infertility of unknown origin diagnosed?

Antonio Forgiarini, gynaecologist at Next Fertility Valencia, tells us in this video how is infertility of unknown origin diagnosed:

We do our visit, we run all the test, we asure that we have a good ovarian reserve, a good number of oocytes... at least what we expect. We expect good ovarian quality because we are talking about young women, because elder women they already have a cause of the sterility. And we asure that the uterus is normal, in the shape, the endometrium is growing well during the menstrual cycle, we have no tubal problems with the Fallopian tubes, the semen is normal... So, when all these things are okay and are normal, we can talk about an unexplained infertility.