Reasons For Infertility
The term infertility is defined as the inability to conceive despite regular and unprotected intercourse for 1 year. However, risk factors such as the woman’s age, abnormal menstrual periods, history of pelvic inflammatory disease and whether there has been previous abdominal or pelvic surgery, history of undescended testicles may warrant earlier investigations and treatment of infertility. It has been found that female factors are responsible in 40% of cases, male factors account for a further 40%, combined male and female factors account for 10% and the remaining 10% of cases are unexplained.
Infertility is classified into two types:
- Primary infertility if there was no previous pregnancy (approximately 40% of infertile couples).
- Secondary infertility if there was a previous pregnancy whatever the outcome (approximately 60% of infertile couples).
Male Factor Infertility
The treatment of male factor infertility is one of the true success stories in the field of reproductive medicine. Male fertility screening is done through semen analysis. Disorders of sperm quality range from a low count or motility to a complete absence of sperm production. Deformities of the sperm cell shape (morphology) are also important to its ability to fertilize the egg. Mild abnormalities of semen parameters can be effectively treated using techniques that “wash” out the seminal plasma and improve the concentration of normally shaped motile sperm, which are then transferred to the uterus via an intrauterine insemination. However, for more severe conditions this treatment is inadequate. With a total motile cell concentration of less than 10 million cells per ml or a normal morphology of less than 4% by strict Kruger criteria, the chance of fertilization failure is very high, even with IVF. As a general principle, if the male factor cannot be reversed in the man’s body, by simple medical or surgical treatment, then IVF with ICSI represents the only rational approach, the results are excellent. Intrauterine insemination is not an effective way of treating mild to moderate male infertility.
The most common causes of low sperm count are temporary and treatable. Research has shown that emotional or physical stress, cigarette smoking or heavy alcohol consumption can affect sperm production and male fertility. Sperm counts usually return to normal levels after such lifestyle issues are addressed. Certain drugs, radiation and radiotherapy may have a detrimental effect on the production of sperm. The presence of a varicocele may lead to a rise in the temperature around the testicles, which may adversely affect sperm production and motility. Testosterone deficiencies and certain autoimmune disorders that cause the body’s defenses to attack developing sperm.
Female Factor Infertility
A woman usually produces a single follicle in the ovaries each month as a result of various hormonal changes. Once the egg which develops within the follicle is mature, it is released. The fallopian tube subsequently picks the egg up and moves it towards the uterus. The quality of cervical mucus at the time of ovulation must be such that it allows free passage of the sperm into the uterus.
There are many different types of infertility experienced by women. Many of the fertility problems can be easily treated. Some of the most common causes of female infertility include tubal blockage, polycystic ovarian syndrome, fibroids and endometriosis. However, there are several other reasons why a woman may experience fertility problems, such as ovulatory disorders (like an ovulation), premature ovarian failure and uterine factors. Egg quality also plays a role in infertility in many women.
The female reproductive system is a very delicate structure that is easily affected by even the slightest change in your body. Because of this, it can be dangerous to alter the system too much. Menstrual suppression, for example, can potentially lead to infertility. Maintaining your health can also help you avoid some infertility risks, like luteal phase defect.
Women with eating disorders find it very difficult to conceive. Anorexics often stop menstruating, making pregnancy impossible until the eating disorder is corrected. Alternately, plus-sized women can also find themselves dealing with various fertility issues.
Age and Fertility
Delayed child bearing is becoming increasingly common in western societies for several reasons: many couples prefer to rear their children only after establishing a stable relationship and financial security, also, there are increasing numbers of late and second marriages.
Although pregnancies in women approaching 50 and beyond are occasionally reported, there is a decrease in fertility (the ability to achieve a pregnancy) with advancing age. The decline is gradual over the reproductive life span of the woman; it is particularly noticeable over the age of 30 and accelerates between 35 and 40 so that fertility is almost zero by the age 45.
A fertilized egg with abnormal chromosomes is the single most common cause of miscarriage: at least half of all miscarriages are due to abnormal chromosomes. The risk of miscarriage is also increased with ageing e.g. the risk of miscarriage at age 25-29 years is 10% while the risk at age 40-44 is 34%. Furthermore, advanced maternal age is associated with an increased risk of chromosomally abnormal offspring.
Unexplained Infertility, cases in which the standard infertility testing has not found a cause for the failure to conceive. Unexplained infertility affects 10% of infertile couples. In the majority of these cases, the failure to reach a diagnosis is not due to inadequate investigations, but is probably due to other factors which cannot be assessed using conventional tests. For example, it is not currently possible to determine if the eggs are actually released at the time of supposed ovulation; if the fallopian tubes are able to pick up the eggs; if the sperm are capable of reaching the site of fertilization; or if the eggs can be fertilized by the sperm.
Diagnosing unexplained infertility is by no means an easy process. It tends to be a diagnosis based on exclusion. Your reproductive endocrinologist will examine you and perform a variety of tests to try to determine exactly what is going on. You may be said to have unexplained fertility if:
- you are ovulating normally
- your fallopian tubes are open and healthy
- you have no pelvic adhesions
- you do not have endometriosis
- your partner has a high sperm count and good sperm motility
- your postcoital test is positive