Infertility or sub-fertility can be generally described as any form of reduced fertility with prolonged time. In 1993, the World Health Organization (WHO) defined the sub-fertility as "lack of conception after at least 12 months of unprotected intercourse". Approximately, a substantial proportion of couples show sub-fertility in the world. According to American Fertility Association - AFA Report, 2006 , the number of couples affected by sub fertility is currently estimated as 15 % of all couples attempting to have children in the world.
Infertility refers to an inability to conceive after having regular unprotected sex. Infertility can also refer to the biological inability of an individual to contribute to conception, or to a female who cannot carry a pregnancy to full term. In many countries infertility refers to a couple that has failed to conceive after 12 months of regular sexual intercourse without the use of contraception.
Studies indicate that slightly over half of all cases of infertility are a result of female conditions, while the rest are caused by either sperm disorders or unidentified factors. According to The Mayo Clinic, USA:
According to Medilexicon's medical dictionary, infertility is "Diminished or absent ability to produce offspring; in either the male or the female, not as irreversible as sterility."
According to the Department of Health and Human Services, USA, approximately 10% to 15% of couples in the USA are infertile - meaning they have not conceived after at least one year of regular, unprotected sex.
Many cases of apparent infertility are treatable. Infertility may have a single cause in one of the partners, or it could be the result of a combination of factors.
Chances of conceiving within one year
In Europe, North America and much of the world approximately 85% of couples will conceive within one year if they have regular unprotected sex. Averages in the UK are as follows (National Health Service):
Therefore, doctors in the UK will not usually diagnose a couple as infertile until 24 months have passed without conception and regular unprotected sex. Most people will see their GP (general practitioner, primary care physician) if there is no pregnancy within 12 months.
According to the National Health Service, UK, a couple that has been trying to conceive for over three years has a maximum 25% chance of conceiving over the subsequent 12 months if they continue trying.
What are the risk factors of infertility?
In medicine, a risk factor is something that raises the risk of developing a condition, disease or symptom. For example, obese people are more likely to develop diabetes type 2 compared to people of normal weight; therefore, obesity is a risk factor for diabetes type 2.
Age - a woman's fertility starts to drop after she is about 32 years old, and continues doing so. A 50-year-old man is usually less fertile than a man in his 20s (male fertility progressively drops after the age of 40).
Smoking - smoking significantly increases the risk of infertility in both men and women. Smoking may also undermine the effects of fertility treatment. Even when a woman gets pregnant, if she smokes she has a greater risk of miscarriage.
Alcohol Consumption - a woman's pregnancy can be seriously affected by any amount of alcohol consumption. Alcohol abuse may lower male fertility. Moderate alcohol consumption has not been shown to lower fertility in most men, but is thought to lower fertility in men who already have a low sperm count.
Being obese or overweight - in industrialized countries overweight/obesity and a sedentary lifestyle are often found to be the principal causes of female infertility. An overweight man has a higher risk of having abnormal sperm.
Eating disorders - women who become seriously underweight as a result of an eating disorder may have fertility problems.
Being vegan - if you are a strict vegan you must make sure your intake of iron, folic acid, zinc and vitamin B-12 are adequate, otherwise your fertility may become affected.
Over-exercising - a woman who exercises for more than seven hours each week may have ovulation problems.
Not exercising - leading a sedentary lifestyle is sometimes linked to lower fertility in both men and women.
Sexually transmitted infections (STIs) - chlamydia can damage the fallopian tubes, as well as making the man's scrotum become inflamed. Some other STIs may also cause infertility.
Exposure to some chemicals - some pesticides, herbicides, metals (lead) and solvents have been linked to fertility problems in both men and women.
Mental stress - studies indicate that female ovulation and sperm production may be affected by mental stress. If at least one partner is stressed it is possible that the frequency of sexual intercourse is less, resulting in a lower chance of conception.