Infertility is the inability to conceive and achieve pregnancy. If you can conceive you are not actually infertile, but this doesn't by any means invariably lead to a successful pregnancy. In general infertility can be divided into primary infertility and secondary infertility; those who have been able to conceive and now can't, and those who have never been able to achieve conception. If you have been able to conceive at some point, that suggests that the anatomy and physiology of your reproductive system, comprising ovaries, fallopian tubes and uterus, was at one time normal. Successful previous pregnancy implies that an ovary was releasing eggs, and the fallopian tubes were not blocked, and the uterus was able to accept implantation of the fertilised egg.
This usually excludes some of the very major and rather rare congenital abnormalities that may occur. However, in most instances primary infertility and secondary infertility have very similar causes. These might include a diminished ability to achieve conception because of age, past pelvic infection, scarring or blocking of the fallopian tubes and ovaries, hormonal imbalance such as polycystic ovary syndrome (PCOS), endometriosis and a whole host of immunological and hormonal dysfunctions, which we are only just beginning to understand with the aid of modern technology. The conventional medical world of assisted conception is one that is changing rapidly and may have much to offer infertile women.