The tube plays a critical role in egg pick-up, sperm transport, fertilization, early embryo development, and subsequent transport of the early embryo back to the uterus. It should, therefore come as no surprise that tubal problems can be a major cause of infertility. Unfortunately, the fallopian tube is very vulnerable to infection, and infection frequently scars the tube and renders it nonfunctional. In fact, tubal scarring (pelvic adhesions) is the leading cause of infertility in the world! In developing countries, tubal infection from systemic tuberculosis is the most common cause. In the United States and Europe, sexually transmitted infections with Chlamydia and gonorrhea are the most common causes of tubal disease. Sexually transmitted diseases can be prevented through the use of barrier contraception such as condoms or abstinence. Endometriosis is also a common cause of tubal scarring.
When the tubes scar near the ends, the fimbriae can get stuck together (called agglutination), making it unlikely for them to function properly in picking up the egg. Severe scarring can even cause the tube to close over entirely and dilate and fill with fluid, a condition called hydrosalpinx. Less severe scarring can close the tube close to the uterus, causing proximal obstruction, preventing the sperm from reaching the egg or preventing the embryo from returning to the uterus.
A tube that works a little bit but not ideally may result in a tubal pregnancy. A tubal pregnancy occurs when a damaged tube is able to pick up an egg and allow fertilization but is unable to transport the embryo back to the uterus. The embryo may therefore implant in the tube itself instead of the uterus. The medical term for a tubal pregnancy is an ectopic pregnancy, meaning a pregnancy that it is in the wrong place. A tubal pregnancy unfortunately cannot be moved back into the uterus. It is important to recognize tubal pregnancies and treat them early, because they can rupture and cause severe internal bleeding. Tubal pregnancies can sometimes be treated with medication to dissolve the tissue if detected very early, or they may require surgery.
Women with infertility problems are at higher risk than the general population for tubal pregnancy. That is why most fertility centers will perform a blood test as soon as the menstrual period is missed. These blood pregnancy levels are then followed closely to see how they are rising. If rising abnormally, there may be suspicion for an ectopic pregnancy. Early ultrasound will also be performed to confirm that the pregnancy has been established in the uterus where it belongs. Approximately 1.5 percent of all pregnancies in the general population are ectopic. In an infertility population, 3-5 percent of all pregnancies are likely to be ectopic. Women with a history of previous tubal pregnancy have an increased chance of both infertility and repeat ectopic pregnancy in the future.
By now you can see what a problem tubal scarring is! Tubal scarring is often detected by an x-ray dye test called a hysterosalpingogram (HSG) or by diagnostic laparoscopy (a small outpatient surgery). If you have tubal scarring, the best option is to have it surgically repaired to improve the function of the tube. If the tube is severely damaged, it may be necessary to remove the tube. It takes a great deal of surgical experience to decide which tube needs to be removed and which needs to be repaired. Do not despair if the tubes cannot be fixed! In Vitro Fertilization works beautifully to bypass damaged tubes. Just don’t wait too long to give IVF a chance, since it works best when you are younger.