Endometriosis is one of the most common reasons for female infertility, and a problem which increases with age. The tissue which usually lines the uterus begins to form in other areas of the body, such as the uterus or the bowel. The cause seems to be during menstruation, when tissue falling off the uterus gets caught elsewhere. It can then begin to grow where it lands.
This in itself might not be such a great problem.
However, since these tissues are originally from the uterus, they try to bleed during menstruation. But, since they aren’t in the uterus, it is difficult for the tissues to leave the body. Thus some of the fluid which would otherwise be menstruated is trapped, and leads to inflammation and irritation. While endometriosis does not inevitably lead to infertility, in many cases it does block the ducts or make it impossible to reach the sperm.
Uterine fibroids are a common but usually harmless condition, affecting perhaps one woman in four. They are non-cancerous tumors within the uterus, most of which are small and can be easily ignored. In a few cases, however, the fibroids block the fallopian tubes, meaning that sperm cannot gain access to fertilize the egg.
The presence of fibroids on the uterus may also make the lining less able to receive the embryo when it is ready to be implanted. It is worth emphasizing how rare this is: even if you are infertile and suffer from uterine fibroids, the two factors are not likely to be connected.
Polycystic Ovary Syndrome
Polycystic ovary syndrome (PCOS), also known as Stein-Leventhal syndrome after the doctors who firs t described it back in the 1930s, is a problem which affects some 5-10% of women, most of whom do not realize that they have it. As well as infertility and irregular menstruation, PCOS is characterized by obesity, acne, and hairiness caused by high levels of male hormones in the blood. The causes are believed to be partly genetic, but the condition remains poorly understood, and it is likely that our understanding of it will change significantly in the coming decades.
How does PCOS cause infertility? Hormone imbalances mean that the ovary does not correctly release follicles. This leaves the ovary with many cysts, which develop from the unreleased follicles. And naturally, since the eggs are not released from the ovaries, they cannot be fertilized.
Suffering from PCOS will not necessarily make you completely infertile.
Physical damage to the reproductive system
Any kind of physical damage to the reproductive system can cause infertility. The fallopian tubes are particularly vulnerable, since injury can easily lead to them being blocked. In Pelvic Inflammatory Disease the fallopian tubes are infected by chlamydia or other bacteria. Infection causes inflammation of the fallopian tubes, which scars the lining. Sometimes this leads to an adhesion, where two sides of the fallopian tubes stick together.
Even after exhaustive tests, it is quite possible that fertility doctors will be unable to find anything medically wrong with you. This is the case for some 10% of couples seeking fertility treatment. Whether you take it as good or as bad news depends somewhat on your temperament.
The former attitude takes it as a hint that perhaps there isn’t anything wrong, that you have just been unlucky and will be able to conceive if you keep trying. This isn’t entirely foolish some one in three couples with unexplained infertility do later manage to conceive. But, as the pessimists will see, it could equally be that you are suffering from some medical problem which has simply not been recognized.
The lack of a clear medical diagnosis will be taken by some as indication that the problem is psychological in nature. This is hard to prove one way or the other, and whether you believe it is in large part determined by whether you see analysts as saints or charlatans.