What is the minimum width of fallopian tubes?

Q: What is the minimum width required for the proper functioning of the fallopian tubes? If the width is lesser than that required, how can it be treated?

A:The lumen of fallopian tube near the uterus is 1 mm and gradually increases up to 2-3 mm towards the fimbrial end without any constriction in between. There is no method to increase the lumen.