How do tubal problems relate to infertility issues?

The fallopian tubes are an important component of natural fertility. The fallopian tube picks up the egg at the time of ovulation and retains it for 24 hours in order for fertilization to take place. Once fertilized, the developing embryo continues to be nourished by fallopian tube fluid for 2-3 more days as it travels down the length of the tube toward the uterus. When fallopian tubes are scarred or blocked as a result of sexually transmitted diseases or pelvic surgery, they either fail to pick up the egg, leading to infertility, or increase the chance of an ectopic pregnancy whereby the embryo implants into the wall of the fallopian tube. When the tube is obstructed at its end, it continues to secrete fluid into its central canal. This fluid collects and causes swelling of the tube, a condition called hydrosalpinx. The fluid from the hydrosalpinx empties into the uterine cavity and can harm embryos. For this reason, it is recommended that hydrosalpinges be surgically removed prior to attempting pregnancy. Tubes that are obstructed closer to the uterus do not typically form a hydrosalpinx but may still cause infertility. To determine if the tubes are open, a hysterosalpingogram can be performed by injecting dye into the uterus and tubes and taking X-ray pictures to track the dye as it flows out the end of the fallopian tube.