The subject of infertility is now at the front burner of many medical and even non-medical discourse all over the world, and rightly so. Infertility is fast attaining epidemic proportions in today’s fast-paced world and is a source of serious concern for many physicians and their patients. A lot about the causes of infertility have been known for many years but new studies have led to the discovery of causes that were either previously unknown or had not been adequately studied. This article focuses on some of the causes of female infertility.
Endocrine diseases (those having to do with hormonal imbalance) are a significant cause of infertility in many women all over the world. However, several environmental, behavioural and structural causes account for a significant number of infertility cases. Some of these are examined below:
Poorly functioning fallopian tubes
Tubal factor infertility (infertility brought on by abnormalities of the fallopian tubes) affects approximately 25 per cent of infertile couples and varies widely. The tubes conduct the egg after it has been released from the ovary into the womb. Tubal abnormalities could range from mild adhesions to complete tubal blockade. When the tubes are blocked, there is no way the released egg can make its way to the womb and this is why affected women cannot get pregnant without intervention.
Treatment for tubal disease is most commonly surgery. Advances in microsurgery and lasers in the management of such cases have pushed success rates (defined as the number of women who become pregnant within one year of surgery) as high as 30 per cent overall, with certain procedures having success rates up to 65 per cent. Development in IVF has now made it a suitable alternative to tubal surgery. The main causes of tubal damage include:
Caused by both bacteria and viruses and usually transmitted sexually. Such may include syphilis, chlamydia and gonorrhoea. Infections commonly cause inflammation of the reproductive tracts, resulting in scarring and damage of the fallopian tubes. A specific example is hydrosalpinx, a condition in which the fallopian tube is occluded at both ends and fluid collects in the tube. Conception even with IVF is problematic for such patients as the fluid that is produced can damage the embryo.
Abdominal diseases and infections
The most common of these are appendicitis and colitis (inflammation of the colon). These present with a high fever and the attending inflammation of the abdominal cavity can affect the fallopian tubes and lead to scarring and blockage.
This is an important cause of tubal disease and damage. Previous pelvic or abdominal surgery such as appendectomy can result in adhesions that alter the natural anatomy of the tubes in such a way that eggs from the ovary cannot smoothly travel through them.
An ectopic pregnancy is one that occurs anywhere outside of the womb. When such a pregnancy occurs within the fallopian tube itself rather than the womb, surgery has to be done to evacuate the conception as it is life-threatening to allow it to progress. However, even when such cases are carefully and successfully managed surgically, tubal damage is still a very high possibility that may later become a primary cause of infertility.
In rare cases, a woman may be born with tubal abnormalities. These cases are usually associated with uterine (womb) abnormalities.
Approximately 10 per cent of infertile couples are affected by endometriosis. It affects five million US women, six to seven per cent of all females. It has been found to be commoner among women who delay having children till the late mid 30s or early 40s for one personal reason or the other. In fact, 30 to 45 per cent of patients with endometriosis are infertile. This is two to three times the rate of infertility in the general population. For women with endometriosis, the monthly fecundity (chance of getting pregnant) diminishes by 12 to 36 per cent.
This condition is characterised by excessive growth of the lining of the uterus, called the endometrium. Growth of endometrial tissue occurs not only in the uterus but also elsewhere in the abdomen, such as in the fallopian tubes, ovaries and the pelvic peritoneum.
The symptoms often associated with endometriosis include heavy, painful and long menstrual periods, urinary urgency, rectal bleeding and premenstrual spotting. Sometimes, however, there are no symptoms at all, owing to the fact that there is no correlation between the extent of the disease and the severity of the symptoms.
The long term cumulative pregnancy rates are normal in patients with minimal endometriosis and normal anatomy. Current studies demonstrate that pregnancy rates are not improved by treating minimal endometriosis.
Abnormalities of the female reproductive organs:
At least 10 per cent of all cases of female infertility are caused by an abnormal uterus. Conditions such as fibroid, polyps, andadenomyosis(over-enlargement of the endometrium) may lead to obstruction of the uterus and fallopian tubes. Congenital abnormalities, such as septate uterus (a double cavity uterus), may lead to recurrent miscarriages or the inability to conceive.
Approximately three per cent of couples face infertility due to problems with the female cervical mucus. The mucus needs to be of a certain consistency and must be available in adequate amounts for sperm to swim easily through it into the womb and fallopian tubes. The most common reason for abnormal cervical mucus is a hormonal imbalance, namely too little estrogen or too much progesterone.