Structure and function of the Fallopian Tube
The Fallopian tubes are complex and delicate structure that are positioned on the upper outer edge of the uterus. They are passages for egg and sperm transport between the ovary and the cavity of the uterus (endometrium). Their main function is to transport eggs and sperm, to permit fertilization and then to carry the embryo back down into the uterus. They are a communication between the outside (vagina) and the internal cavity of the abdomen (peritoneal cavity). The Fallopian tubes are approximately 11 centimetres in length. The lining of the tubes secrete nourishing fluids for eggs, sperm and embryos. Because of their crucial role in reproduction and disease, dysfunction or distortion can have a profound effect on the prospects of achieving a successful pregnancy. As such damage to the fallopian tubes is a relatively common cause of infertility.
Pelvic Infection
Infection is the commonest reason for damage to the Fallopian tubes. Such infection is called salpingitis and may be due to sexually transmitted diseases such as Gonorrhoea and Chlamydia. It is also caused by other non-sexually related bacteria from the urinary or gastrointestinal systems. Salpingitis may be acute or chronic. Unfortunately, salpingitis may occur without any obvious symptoms and so the first time it may become obvious is during the investigation of infertility when evidence of damage is discovered at laparoscopy. The tubes can be bound down to other structures by adhesions or can become permanently blocked. Pain is commonly associated with these adhesions.
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Hydrosalpinx is a longer term complication of salpingitis - this is where the tube is blocked at the outer end and then fills with a watery fluid. This fluid is the result of inflammation and is toxic to embryos. The presence of a hydrosalpinx markedly reduces the chance of successful pregnancy - even when IVF is used to treat infertility. |
Hydrosalpinx |
Once damage has occurred it cannot be totally repaired, although it may be possible to re-open fallopian tubes to reduce the number and extent of adhesions in the pelvis by microsurgery.
Ectopic Pregnancy
Any pregnancy that implants in other than a normal position within the uterine cavity is known as an ectopic pregnancy. Most commonly ectopic pregnancies occur in the Fallopian tube but they can occur within the cervix, ovary or other sites outside the uterus within the abdominal cavity. Ectopic pregnancies commonly cause irreparable damage to the Fallopian tube and so limit the future prospects of a normal pregnancy.
Tubal Ligation
It is self evident that prior tubal ligation - for contraception will prevent pregnancy. On the other hand, due to change of partner or life circumstances some women will desire pregnancy after tubal ligation. Microsurgical tubal ligation reversal or IVF are alternative managements.
Previous surgery, appendicitis or complications from ovarian cysts can also cause Fallopian tube damage. Severely damaged tubes can be by-passed using IVF (In Vitro Fertilization).