A hydrosalpinx is an abnormal pouch containing liquid in a fallopian tube. It can be a complication occurring after salpingitis, or a tubal infection. The fallopian tubes are conduits through which the egg travels toward the uterus, and it is in these tubes that most fertilization happens. So if hydrosalpinx affects both tubes, infertility can be the result. Hydrosalpinx isn't usually responsible for any symptoms but can sometimes cause mild pain. Hydrosalpinx can be identified by ultrasound, and its treatment is surgical.