No, the blocked fallopian tubes does not affect the menstrual cycle. Function of the tubes is just to transport ovum from ovaries to uterus.
The transvaginal sonography is unable to detect the blockage in tubes. The investigation done to detect block is called Hysterosalpingography (HSG). This procedure involves a series of X-rays taken. A dye is injected into the cervix and travels up to the fallopian tubes. The dye enables the X-ray to reveal if the fallopian tubes are open or blocked.
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