Answer from: Patricio Calamera, MD, MSc, ObGyn
Unexplained vs. idiopathic female or male infertility, it is talking about the same thing. There is no actual real difference. We use unexplained or idiopathic to refer to things that we don’t know what is the mechanism behind, what is going wrong. It is not very difficult to explain, it is basically the same. It is not a big deal if we call it unexplained or idiopathic. The thing is that either way we still don’t know what is going on and we need to study further.
Answer from: Jane Stewart, MD
Idiopathic really means that you don’t know what’s going on but it doesn’t mean that there is not a problem identified. So for instance if you talk about idiopathic male factor infertility we have identified a male factor problem. There may be a low sperm count for instance but we don’t know why that is. There are some very specific reasons why men have problems with their sperm production but actually there is a whole range of levels of sperm production some of which will be suboptimal in males and reduce the chance of natural fertility. That is idiopathic because we don’t know why that is but there is a cause there, or a cause for the fertility problem. For women, a similar thing might be premature ovarian insufficiency, where for instance there is either low ovarian reserve or the ovaries stop working completely, which is often idiopathic. We know there’s a problem but we don’t know the cause of it. There are very specific problems there of an unknown cause. Unexplained subfertility is different because in that setting, what we are really saying is that the whole process of infertility is idiopathic, we just don’t know why the fertility is not happening. Everything looks to be okay but there is something else going on perhaps that is causing the problem. It is a slightly different thing as it is not an absolute, neither of those idiopathic things in fertility terms but there is an absolute factor there that we can see even if it doesn’t cause fertility problems.
