The Absence of Ovulation
There are many causes of anovulation (an absence of ovulation), and a wide variety of symptoms which enable us to identify these. In some circumstances anovulation can be treated with medicine, and in others, changes to lifestyle are sufficient. Unfortunately in some cases it is untreatable and pregnancy can only be achieved with the aid of an egg donor. Some of the treatable causes are as follows:
- Hypothalamic anovulation: caused by exercise, stress and/or weight loss.
- Hyperprolactinemia: increased levels of prolactin, a hormone produced in the hypophysis.
- Polycystic Ovarian Syndrome (PCOS): this is the most common cause of irregularities in ovulation, and a very significant cause of infertility. Women who have this syndrome have enlarged ovaries with many small undeveloped follicles (wrongly called "cysts"). This syndrome is sometimes associated with obesity and hormonal upsets which can make it difficult to conceive.
Fallopian tube obstruction
The Fallopian tubes can be blocked for the following reasons:
- Salpingitis: this is an inflammation of the Fallopian tubes, and it can occur by the infection entering and spreading through the vagina and on up to the uterus, as with sexually transmitted diseases such as gonorrhoea and Chlamydia, although it can also come from outside of the Fallopian tubes through the infection being spread from other organs such as the appendix. When this happens, the tubes, frequently damaged by adhesions, become obstructed. The obstruction can take two forms: it can cause a separation between the ovary and the tube caused by adhesive tissue, or a blockage at the outer end of the tube. Adherence can also occur following pelvic surgery or as a result of endometriosis.
- Hydrosalpinx: a hydrosalpinx is a particular type of obstruction of the tubes in which the duct is blocked near its distal end, the fimbria. The fimbriae are the fringe-like formations located at the ends of the Fallopian tubes. These fimbriae enable the ovum to enter the tube when it leaves the ovary, so that it can be fertilised by a spermatozoon and then pass towards the uterus as cell division takes place and become implanted as an embryo. The fimbriae are made up of delicate cells which contain motile cilia, which transport the ovum and spermatozoa so that they come together. When they are damaged, these fimbriae stick together and the delicate cells described above are ruined. This means that fluid accumulates in the closed circuit of the tube and that its nourishing effect is lost. A hydrosalpinx generally arises as the result of an infection. The classic infections are from Chlamydia and gonorrhoea, which can remain undetected for years, damaging and destroying the delicate fimbriae. IUDs, endometriosis and abdominal surgery are also associated with the problem.
- Pyosalpinx: a pyosalpinx is an acute inflammation in the tubes which become blocked because they are filled with pus. Sometimes the infection abates in response to antibiotics, and it becomes a hydrosalpinx. At the other extreme, it may rupture and form an abscess in the pelvis.
- Congenital blockage of the Fallopian tubes: there can be problems with the tubes from birth (congenital obstruction of the tubes).
- Deliberate obstruction of the tubes: tubal ligation (as a contraceptive method).
- Accidental damage following surgery: for example, after abdominal surgery, causing adhesions.
Endometriosis is a process whereby material similar to the lining of the uterus (the endometrium) begins to grow outside of the uterus. It is a very common disorder, especially in women above the age of 30 who have not had children, and its nature is unknown.
Severe endometriosis can distort both the Fallopian tubes and the ovaries and can have a profound effect on fertility. The cause of endometriosis is not known and it is usually benign, but it is difficult to control and on some occasions it can lead to a loss of healthy ovarian tissue and cause adhesions in the female reproductive system.
Endometriosis can be confirmed by a laparoscopy (inserting a small camera into the abdominal cavity through a small incision in the navel) and can often be treated at the same time.
It can also be treated by non-surgical methods such as hormone therapies. These treatments can help to alleviate the symptoms of endometriosis, but as they prevent ovulation they cannot improve fertility.
- Myomas or fibroids: myomas, or fibroids, are benign tumours which grow from the myometrium (the wall of muscular fibres comprising the uterus and which surrounds the endometrium). Myomas could be caused by failed implantation or by miscarriage, which is especially the case the closer they are to the endometrium; they may also be related to symptoms such as excessive bleeding or dysmenorrhea.
- Unexplained or idiopathic causes: In about 5 - 6% of couples it is not possible to establish the cause of infertility, even after carrying out rigorous tests.