If you are hirsute because of anorexia or being underweight, the thinness, not the hirsutism can cause you to skip periods or stop having them altogether. The lack of periods can make a woman infertile but not the hirsutism.

If you have hirsutism because of pcos, then you may have trouble conceiving- but that is because of the actual disorder, not the hirsutism itself. If you have hirsutism by some cause other than pcos, then I'm not quite sure, but I would really like to know the same, if anyone knows!