In natural unassisted conception, the fallopian tubes play an integral part in establishing pregnancy. First, an egg which is ovulated from the adjacent ovary must be picked up by the finger-like projections at the end of the tube. The ovulated egg is safe-guarded in the ampullary segment of the tube until it is fertilised by sperm. The tube nurtures the resulting embryo for the next five days as it traverses the length of the tube before entering the uterus. Tubal factor infertility pertains to tubal damage which precludes interaction between egg and sperm and/or prevents the proper movement of embryos along the tube for uterine implantation.
The fallopian tubes are delicate structures of only about the same thickness as the lead of a pencil. Because of this they can easily become blocked or damaged. This can interfere with the sperm reaching the egg, and a proper embryo development and implantation in the uterus. Blockages may arise as a result of scarring due to infection or previous abdominal surgery.
Pelvic inflammatory disease (PID) is usually the main cause of tubal infertility. In addition PID is associated with an increased risk of subsequent ectopic pregnancy (when the fertilised egg implants in the fallopian tube instead of the uterus).
What the Fallopian tubes do
- To “grab” the oocyte as soon as it is released from the ovary at the time of ovulation. To perform this function the fallopian tubes must be freely movable and must not be stuck to the pelvic wall, uterus or ovaries by adhesions.
- To function as an incubator where the oocyte and sperm meet and the initial stages of embryo development takes place. For this function the tubes must be patent (open).
- The inside lining of the fallopian tubes act as a conveyor system moving the developing embryo to the uterus where it implants 3 – 5 days after ovulation.
Causes of Fallopian Tube damage
- The use of the intra-uterine contraceptive device (contraceptive “loop”) especially when there are more than one sexual partners.
- Sexually transmittable disease such as gonorrhoea resulting in infection of the fallopian tubes.
- Previous pelvic surgery especially when the fallopian tubes or ovaries were involved. The competence of the surgeon is crucial in limiting post-operative damage.
The diagnosis of tubal damage is established with a pelvic x-ray called a hysterosalpingogram (HSG). The test involves the injection of dye into the uterine cavity and a simultaneous x-ray of the uterus and tubes, which illustrates the dispersion of dye through the pelvic organs.
- Tubal surgery: When tubal surgery is indicated the laparoscopic route is also usually more preferable to “open surgery”. The feasibility for the surgery depends on the severity of tubal damage and the position where the Fallopian tube is damaged. A competent infertility specialist is absolutely essential to perform tubal surgery effectively.
- In Vitro-Fertilisation: If tubal surgery is not feasible due to extensive tubal damage, In Vitro-Fertilisation is the only option. Please read about IVF under infertility treatments.
Damage to the Fallopian Tubes includes
- Total blockage preventing sperm and oocytes to meet and to produce an embryo.
- Reduced mobility which results in the inability of the fallopian tube to pick up the egg when it is released from the ovary.
- Damage to the inside wall of the fallopian tube which results in the inability of the embryo to move down to the uterus. This may result in an ectopic pregnancy if the embryo attaches to the side wall of the fallopian tube resulting in rupturing of the tube at about seven weeks pregnancy duration.
Medfem Fertility Clinic offers both advanced microsurgical treatments as well as in vitro fertilisation as therapy for tubal factor infertility.