Is usg a definitive test to determine fibroids that could cause fertility issues?

Submucus fibroids: Its generally considered a reliable test for polyps, fibroids and other abnormalities inside the uterine cavity. Fibroids outside the uterine cavity are less likely to have a major impact on fertility.

Not defnitive: Ultrasound can identify most fibroids in the uterus but not necessarily all of them, especially if they are small. Most fibroids do not cause infertility although some may be associated with miscarriages, preterm delivery, bleeding, pain, etc.