Infertility

Infertility



Definition of İnfertility 

Definitions of infertility differ, with demographers tending to define infertility as childlessness in a population of women of reproductive age, while the epidemiological definition is based on “trying for” or “time to” a pregnancy, generally in a population of women exposed to a probability of conception. The time that needs to pass (during which the couple has tried to conceive) for that couple to be diagnosed with infertility differs between different jurisdictions. Existing definitions of infertility lack uniformity, rendering comparisons in prevalence between countries or over time problematic, and therefore data estimating the prevalence of infertility cited by various sources differs significantly. A couple that has tried unsuccessfully to have a child after a certain period of time (often a short period, but definitions vary) is sometimes said to be subfertile, meaning less fertile than a typical couple. Both infertility and subfertility are defined as the inability to conceive after a certain period of time (the length of which vary), so often the two terms overlap.

Causes of İnfertility

This section deals with unintentional causes of sterility.

Causes in either sex

Factors that can cause male as well as female infertility are:

  • DNA damage
    • DNA damage reduces fertility in female ovocytes, as caused by smoking, other xenobiotic DNA damaging agents (such as radiation or chemotherapy) or accumulation of the oxidative DNA damage 8-hydroxy-deoxyguanosine
    • DNA damage reduces fertility in male sperm, as caused by oxidative DNA damage, smoking, other xenobiotic DNA damaging agents (such as drugs or chemotherapy) or other DNA damaging agents including reactive oxygen species, fever or high testicular temperature
  • Genetic factors
    • A Robertsonian translocation in either partner may cause recurrent spontaneous abortions or complete infertility.
  • General factors
    • Diabetes mellitus, thyroid disorders, adrenal disease
  • Hypothalamic-pituitary factors
    • Hyperprolactinemia
    • Hypopituitarism
    • The presence of anti-thyroid antibodies is associated with an increased risk of unexplained subfertility with an odds ratio of 1.5 and 95% confidence interval of 1.1–2.0.
  • Environmental factors
    • Toxins such as glues, volatile organic solvents or silicones, physical agents, chemical dusts, and pesticides. Tobacco smokers are 60% more likely to be infertile than non-smokers.

German scientists have reported that a virus called Adeno-associated virus might have a role in male infertility, though it is otherwise not harmful. Mutation that alters human DNA adversely can cause infertility, the human body thus preventing the tainted DNA from being passed on.

Specific female causes

The following causes of infertility may only be found in females. For a woman to conceive, certain things have to happen: intercourse must take place around the time when an egg is released from her ovary; the systems that produce eggs and sperm have to be working at optimum levels; and her hormones must be balanced.

For women, problems with fertilisation arise mainly from either structural problems in the Fallopian tube or uterus or problems releasing eggs. Infertility may be caused by blockage of the Fallopian tube due to malformations, infections such as chlamydia and/or scar tissue. For example,endometriosis can cause infertility with the growth of endometrial tissue in the Fallopian tubes and/or around the ovaries. Endometriosis is usually more common in women in their mid-twenties and older, especially when postponed childbirth has taken place.

Another major cause of infertility in women may be the inability to ovulate. Malformation of the eggs themselves may complicate conception. For example, polycystic ovarian syndrome is when the eggs only partially developed within the ovary and there is an excess of male hormones. Some women are infertile because their ovaries do not mature and release eggs. In this case synthetic FSH by injection or Clomid (Clomiphene citrate) via a pill can be given to stimulate follicles to mature in the ovaries.

Other factors that can affect a woman’s chances of conceiving include being over or underweight, or her age as female fertility declines sharply after the age of 35. Sometimes it can be a combination of factors, and sometimes a clear cause is never established.

Common causes of infertility of females include:

  • ovulation problems (e.g. polycystic ovarian syndrome, PCOS, the leading reason why women present to fertility clinics due to anovulatory infertility.)
  • tubal blockage
  • pelvic inflammatory disease
  • age-related factors
  • uterine problems
  • previous tubal ligation
  • endometriosis
  • advanced maternal age

Specific male causes

The main cause of male infertility is low semen quality. In men who have the necessary reproductive organs to procreate, infertility can be caused by low sperm count due to endocrine problems, drugs, radiation, or infection. There may be testicular malformations, hormone imbalance, or blockage of the man’s duct system. Although many of these can be treated through surgery or hormonal substitutions, some may be more indefinite. Infertility associated with viable, but immotile sperm may be caused by primary ciliary dyskinesia.

Combined infertility

In some cases, both the man and woman may be infertile or sub-fertile, and the couple’s infertility arises from the combination of these conditions. In other cases, the cause is suspected to be immunological or genetic; it may be that each partner is independently fertile but the couple cannot conceive together without assistance.

Unexplained infertility

In the US, up to 20% of infertile couples have unexplained infertility. In these cases abnormalities are likely to be present but not detected by current methods. Possible problems could be that the egg is not released at the optimum time for fertilization, that it may not enter the fallopian tube, sperm may not be able to reach the egg, fertilization may fail to occur, transport of the zygote may be disturbed, or implantation fails. It is increasingly recognized that egg quality is of critical importance and women of advanced maternal age have eggs of reduced capacity for normal and successful fertilization. However recent data indicates that the egg quality, measured by ovarian reserve markers such as FSH and AMH, are key indicators of the success of fertility treatments, but do not affect the chances of assisted natural conception beyond maternal age and time trying to conceive  Also, polymorphisms in folate pathway genes could be one reason for fertility complications in some women with unexplained infertility.

Signs and symptoms of Infertility

The main symptom of infertility is the inability to achieve a successful pregnancy. Most couples achieve pregnancy within the first six months of trying. Overall, after 12 months of unprotected intercourse, approximately 90 percent of couples will become pregnant. There is no other obvious symptom.

In general, a hormone problem or a problem with the structure or function of the reproductive tract can cause infertility. Men and women will have different symptoms.

Infertility Symptoms in Women

In women, symptoms include:

  • Bleeding is heavier or lighter than usual.
  • Menstruation irregularly or not at all
  • Abnormal ovulation. If your ovaries do not release eggs, you cannot get pregnant.
  • Painful periods. Significant pelvic pain. Back pain and cramping may also occur.

Infertility Symptoms in Men

Infertility symptoms in men can be vague. They may go unnoticed until pregnancy is attempted.

Symptoms depend on what is causing the infertility. They may include:

  • Changes in hair growth
  • Changes in sexual desire
  • Low sperm count
  • Pain, lump, or swelling in the testicles
  • Problems with erection and ejaculation
  • Small, firm testicles

Risk Factors For Infertility

Many of the risk factors for both male and female infertility are the same. They include:

  • Age: women in their late 30s are generally less fertile than women in their early 20s. Infertility in older women may be caused by a higher rate of chromosomal abnormalities that occur in the eggs as they age or to health problems that may interfere with fertility. Men older than age 40 may be less fertile than are younger men.
  • Tobacco smoking: Smoking also reduces a couple’s chance of achieving a pregnancy and the possible benefit of fertility treatment. Miscarriages are more frequent in women who smoke.
  • Alcohol use: For women, there’s no safe level of alcohol use during conception or pregnancy. The risk of birth defects is increased by it, and it may also — at moderate to heavy levels — make it more difficult to become pregnant. Moderate alcohol use does not appear to decrease male fertility.
  • Weight: Being overweight or being underweight may cause infertility. Women at risk include those with eating disorders, such as anorexia nervosa or bulimia, and women following a very low calorie or restrictive diet.
  • Too much exercise: In some studies, exercising more than seven hours a week has been associated with ovulation problems. On the other hand, not enough exercise can contribute to obesity, which also increases infertility.

Diagnosis of Infertility

If both partners are young and healthy and have been trying to conceive for one year without success, a visit to the family doctor could help to highlight potential medical problems earlier rather than later. The doctor may also be able to suggest lifestyle changes to increase the chances of conceiving.

Women over the age of 35 should see their family doctor after six months as fertility tests can take some time to complete, and age may affect the treatment options that are open in that case.

A family doctor takes a medical history and gives a physical examination. They can also carry out some basic tests on both partners to see if there is an identifiable reason for not having achieved a pregnancy. If necessary, they refer patients to a fertility clinic or local hospital for more specialized tests. The results of these tests help determine the best fertility treatment.

Prevention from Infertility

Most types of male infertility aren’t preventable. However, a woman can increase her chances of becoming pregnant in a number of ways:

  • Regular exercise is important, but avoid exercising intensely.
  • Maintain a healthy diet
  • Quit smoking, avoid excessive alcohol consumption, and illegal drugs
  • Limit the use of medications
  • Limit caffeine intake

Smoking, excessive alcohol consumption and drugs may contribute to male infertility. Avoid them and hot tubs and steam baths because high temperatures can affect sperm production and motility.

Treatments of İnfertility

Treatment depends on the cause of infertility, but may include counselling, fertility treatments, which include in vitro fertilization. According to ESHRE recommendations, couples with an estimated live birth rate of 40% or higher per year are encouraged to continue aiming for a spontaneous pregnancy. Treatment methods for infertility may be grouped as medical or complementary and alternative treatments. Some methods may be used in concert with other methods. Drugs used for women include Clomiphene citrate, Human menopausal gonadotropin, Follicle-stimulating hormone, Human chorionic gonadotropin, Gonadotropin-releasing hormone analogs, Aromatase inhibitor, Metformin.

At-home conception kit

In 2007 the FDA cleared the first at home tier one medical conception device to aid in conception. The key to the kit are cervical caps for conception. This at home [cervical cap] insemination method allows all the semen to be placed up against the cervical os for six hours allowing all available sperm to be placed directly on the cervical os. For low sperm count, low sperm motility, or a tilted cervix using a cervical cap aids conception. This is a prescriptive medical device, but not commonly prescribed by physicians.

Medical treatments

Medical treatment of infertility generally involves the use of fertility medication, medical device, surgery, or a combination of the following. If the sperm are of good quality and the mechanics of the woman’s reproductive structures are good (patent fallopian tubes, no adhesions or scarring), physicians may start by prescribing a course of ovarian stimulating medication. The physician may also suggest using a conception cap cervical cap, which the patient uses at home by placing the sperm inside the cap and putting the conception device on the cervix, or intrauterine insemination (IUI), in which the doctor introduces sperm into the uterus during ovulation, via a catheter. In these methods, fertilization occurs inside the body.

If conservative medical treatments fail to achieve a full term pregnancy, the physician may suggest the patient undergo in vitro fertilization (IVF). IVF and related techniques (ICSI, ZIFT, GIFT) are called assisted reproductive technology (ART) techniques.

ART techniques generally start with stimulating the ovaries to increase egg production. After stimulation, the physician surgically extracts one or more eggs from the ovary, and unites them with sperm in a laboratory setting, with the intent of producing one or more embryos. Fertilization takes place outside the body, and the fertilized egg is reinserted into the woman’s reproductive tract, in a procedure called embryo transfer.

Other medical techniques are e.g. tuboplasty, assisted hatching, and Preimplantation genetic diagnosis.