What oviduct conditions can cause infertility?

Several conditions of the oviduct (fallopian tube) can impair fertility: tubal blockage (e.g., due to infection or endometriosis), damage of cilia (reducing transport), ectopic pregnancy in the tube, adhesions or scarring, hydrosalpinx (fluid filled tube) that impairs implantation, and congenital malformations of the tube. Each of these disrupts sperm-egg meeting or embryo transport to uterus.