The fallopian tubes are very important organs of the female reproductive system. After the egg is released from the ovary (ovulation), the tubes hold the egg which remains there waiting to be fertilised. Fertilisation occurs within 24 after ovulation, if there is already sperm in the fallopian tubes. Normal tubes secret hormones that are necessary for fertilisation. Once the egg is fertilised, it remains in the tube for 48 hours before it descends to the uterus.
It is obvious that in cases where the tubes are obstructed for any reason it is impossible to achieve fertilisation or a pregnancy. In women with total obstruction, natural conception is impossible. In cases where there are adhesions, it is also very difficult, yet not impossible, to achieve a pregnancy. Women with adhesions in the tubes are in risk of ectopic pregnancy because the fertilised embryo does not descend to the uterus and remains in the tube.
In-vitro fertilisation as a method of treatment was originally recommended to women with obstructed tubes. During IVF, the egg is taken from the ovaries and is fertilised in the lab instead of the fallopian tube. Two or three days later, the embryo is transferred into the uterus.
What causes tube obstruction?
Pelvic infection is the main cause of tube obstruction. The infection is caused by bacteria already existing in a woman’s reproductive tract or by bacteria transmitted through sexual intercourse. Many women with obstructed tubes have a history of pelvic infection with pain, fever and vaginal discharge. However, up to 50% of women with obstruction never had such symptoms. In these cases, tube obstruction is diagnosed during hysteroscopy or laparoscopy.
Chlamydia and, less commonly, mycoplasma can cause infection without any symptoms (pain or discharge). Chlamydia are transmitted during sexual intercourse and can be detected in cervical mucus. In that case, the doctor prescribes an antibiotic to both partners for 10 days. However, if Chlamydia are detected in the cervical mucus it does not necessarily mean that the tubes are obstructed. Women with Chlamydia infection face a 25% chance of obstructed tubes. If a woman had 2-3 episodes of Chlamydia infection, her chances of having a tubal obstruction reach 50-60%.
Infection and tubal obstruction may happen following surgery in the uterus such as abortion, excision of HPV-affected tissues etc. During these procedures, micro-organisms from the vagina and the cervix might be transported into the uterus. This is why it is recommended to prescribe antibiotics for Chlamydia and other common pathogens to the patient as a precaution. We recommend that the patient starts on antibiotics 24 hours prior to the operation and then continue for 7 days post –op.
Intra-uterine devices (IUD) for contraception are another cause of pelvic infection and tube obstruction. IUDs can cause intrauterine adhesions and tubal obstruction in some women. Therefore, IUDs are not recommended to women who want to get pregnant eventually. The woman should take antibiotics when the IUD is placed in order to avoid pelvic infection.
Other causes of tubal obstruction are endometriosis and adhesions from previous operations in the pelvis. In both cases, the cause of adhesions and obstructions is the trauma to the peritoneum. So, procedures such as appendicitis (especially neglected cases or appendix rapture) or intense diathermy of the ovaries or ovarian cyst removal may cause adhesions and therefore tubal obstruction.
Obstruction of tubes that appear normal is detected with a dye test during laparoscopy. In that case the dye does not go through the tubes. In other cases, tubes appear swollen or may contain fluid (hydrosalpinx) or pus (pyosalpinx).
What is the treatment for tubal obstruction?
In mild cases, especially when only the end part of the tube is affected, surgery might help. Laparoscopy is useful in cases of adhesions, however obstruction is usually so extended that surgery is a waste of time. In these cases, IVF is the only solution. Many specialists suggest that a damaged tube or a tube containing fluid (hydrosalpinx, pyosalpinx) should be removed before the fertility treatment. Many researchers believe that the fluid flows to the uterus and affects the uterine environment. This means that women with hydrosalpinx have a lower success rate when following an IVF treatment.