Fibroid is a tumor detected in the uterus and contains cells similar to muscle cells. The size and the exact location in the uterus might vary, thus causing a variety of symptoms. These symptoms include: hemorrhage, painful and heavy periods, abdominal discomfort, bleeding during intercourse, etc. They might even be a cause for infertility when the inner lining of the uterus cannot be prepared for embedding the fertilized egg. Although, in this case, fibroid is one of the rarer causes for infertility.
Tumors that are formed from fibrous tissue might be found on the ovaries (fibroma), but are not called fibroids. Assuming that you actually talked about fibroma, they might affect the function of the ovaries. The functional tissue of the ovaries might be significantly reduced thus increasing the chances for hormone production irregularities. The releasing of the eggs from the ovaries might also be affected, thus relating this condition with irregular ovulation.
You might want to visit a gynecologist for more information on this issue.