It is not enough to just have an open tube. Apart from being a passage for sperm and egg to meet, it has lots of other functions, which are vital to get pregnant. It would be difficult to conceive with tubes that are open but not doing its function properly.
So what are the functions of a normal fallopian tube?
Picking up eggs after ovulation – During ovulation the fallopian tube covers the ovary and picks up the egg by muscular action and ciliary action (small brush like structures inside the fallopian tube, which beats in one direction to move the egg inwards into the tube).
Sperm capacitation: Capacitation is the changes that sperm must undergo before it fertilises the egg. This is crucial as it makes the sperm more active, energetic and gives it the ability to penetrate the egg. Capacitation happens in the fallopian tube.
Transporting egg and sperm to the middle of the tube by muscular and ciliary action.
Nourishing sperm and egg – the eggs and the sperm are nourished by the tubular fluid during their stay in the tube.
Nourishing embryo for 4 days – after fertilisation, the embryo stays in the tube for 4 days before being moved to the uterus on the 5th day. During these 4 days, the fluid in the tube provides the ideal environment for the embryo to survive and keep developing.
Transporting embryo towards uterus – the tube plays active role in propelling the embryo to the uterus. In absence of proper tubal function, the embryo stays in the tube and gets implanted leading to ectopic pregnancy.
Tubal function is crucial for pregnancy. Having a patent tube does not mean that tubes are functioning well.
What causes tubal dysfunction?
Subtle infection can cause damage to the structure of the tubes, which can cause tubal dysfunction. Infection can be caused by:
Sexually transmitted infections like milder forms of chlamydia infection, gonorrhoea infections can cause damage to the tubes, even if you had no symptoms.
Termination of pregnancy,
Having had coil for contraception,
Delivery and post pregnancy infection
Open abdominal surgery
Smoking can cause damage to the tubes and increase the risk of ectopic pregnancy. Both active and passive smoking can cause damage to the tubes.
Endometriosis – pelvic adhesions (scar tissues) can cause distortion of the tubes. Even if they are open and normal, they might not be fully mobile and hence unable to transport the sperm, egg and the embryo.
Previous ectopic pregnancy: An ectopic pregnancy will undoubtedly damage the tube and cause tubal dysfunction. Hence he risk of another ectopic pregnancy is high after one ectopic pregnancy. Even if the unaffected tube is open, it is doubtful how well it is functioning.
Subtle infection, smoking (both active and passive), endometriosis can cause tubal damage
How do I know if my tubes are functioning properly?
Unfortunately, there are no tests available to assess the tubal function.
The tubal patency test like HSG/HyCoSy/laparoscopy and dye test only assesses whether the tube is open or closed. Even if the tube is open, it might not function properly leading to difficulty in conceiving.
If there are symptoms suggestive of endometriosis, then laparoscopy and dye test should be done. Treatment of mild endometriosis will improve the chances of normal conception.
The tests that assesses tubal patency DO NOT tell us whether it is functioning properly
What can be done to improve my chances of pregnancy?
A careful history taking is mandatory to identify the risk factors for tubal damage. In presence of the risk factors you would need tubal patency test. However, be mindful of the risk of tubal dysfunction even if the tubes are open.
In presence of significant risk factors for tubal damage, IVF is needed if no pregnancy occurs in 2 years.
A careful history taking to identify the risk factors for tubal damage is essential
I have one tube blocked and one tube open – can I get pregnant?
If one tube is open there is every chance of natural conception.
However, the infection that has caused the tubal blockage on one side could have an impact on the other tube as well. Even if the other tube is open it might not be functioning well.
So if conception does not occur in 1-2 years, then it would be better to move on with IVF.
Written by Dr Anupa Nandi