Blocked fallopian tubes. Coloured hystero- salpinogram (X-ray) of the reproductive tract of a women with blocked fallopian tubes, a condition known as hydrosalpinges. The fallopian tubes lead off either side of the top of the uterus (centre, orange). Part of the left fallopian tube (at upper right) shows a large accumulation of fluid (yellow) and there are smaller dilations in both tubes. Hydrosalpinx is the accumulation of fluid in, and dilation of, a damaged fallopian tube. The damage is a result of pelvic inflammation, most often caused by sexually transmitted diseases. Blocked fallopian tubes are a cause of infertility. Treatment is either with surgical unblocking or removal of the tubes.