1 in 8 couples in the U.S suffer from infertility, and there are many different causes. Tubal factor infertility affects approximately 20% of women who are having issues with fertility. Normal fallopian tubes are extremely important since fertilization (union of the sperm and egg to form an embryo) takes place in the tube. When the egg is released from the ovary at the time of ovulation, it is picked up by the finger-like projections at the end of the fallopian tubes. The egg then travels to meet the sperm within the fallopian tube. After fertilization, the fertilized egg is now called an embryo, and it travels through the fallopian tube into the uterus to implant and result in a pregnancy.
As you can imagine, if the fallopian tubes are blocked, the sperm will never be able to make it to the egg. The blockage can be proximal (where the fallopian tube connects to the uterus) or distal (at the end of the fallopian tube, close to the ovary). Sometimes proximal blockage can be due to mucous or debris and can be “unblocked” surgically. Sometimes there is scarring - such as due to an old infection – and such tubes may not be able to be surgically “opened”. With distal occlusion, if the fallopian tube is dilated and full of inflammatory fluid, it is called a hydrosalpinxand these tubes typically are too damaged to salvage. Even for couples undergoing In-vitro fertilization (IVF) where fallopian tubes are not required, a hydrosalpinx should be removed prior to proceeding with IVF since it can decrease pregnancy rates by 30%. This may be secondary to inflammatory fluid leaking into the uterus, but the exact etiology is not known. If the distal occlusion is mild, it may be able to be corrected by a fimbrioplasty or neosalpingostomy.
In addition, there are factors such as pelvic inflammatory disease (PID) and endometriosis that can cause altered fallopian tube function even if they are open; damaged fallopian tubes can increase the risk of tubal (ectopic) pregnancy. PID can result in a tubal abnormality called salpingitis isthemica nodosa (SIN) which greatly increases risk of an ectopic pregnancy.
As you can see, fallopian tubes are an extremely important factor for normal fertility. There is a screening test called a hysterosalpingogram(HSG) which can help to assess the openness of the fallopian tubes. During this test, the radiologist injects dye into the uterus. If the fallopian tubes are open, the dye should travel from the uterus, through the fallopian tubes, and out into the pelvic cavity. This is part of the basic evaluation for infertility and one of the first few things ordered for any woman undergoing an infertility evaluation.
