What is normal fertility?
For normal fertile couples the chance of achieving a successful pregnancy is:
- 20% for any given month
- 57% within three months of trying
- 75% within six months
- 90% within one year and
- 95% within two years of attempting pregnancy
Who is affected by infertility?
One in six couples attempting pregnancy will have difficulty achieving pregnancy.
The ability to achieve a successful pregnancy declines with age:
- 25% of women have difficulty conceiving between the ages of 35-39
- 34% of women will have difficulty achieving pregnancy by age 40
A problem with the male is a contributing cause of infertility in about 50 percent of infertile couples.
One third of infertile couples have more than one cause or factor related to their inability to conceive.
In 10 to 20 percent of couples, the cause of infertility cannot be determined.
What causes infertility?
Approximately 25% of all infertile women have problems with ovulation.
- Hormonal imbalances may be caused by extremely low body weight, being overweight.
- Polycystic ovarian syndrome (PCOS) is affecting 5% to 10% of women of childbearing age. Symptoms may include irregular or absent periods, high blood pressure, acne, elevated insulin levels, excess hair on the face and body, and weight problems.
A woman’s fallopian tubes become damaged or blocked because of:
- Past infections – Pelvic inflammatory disease (PID) is caused by a type of bacteria such as chlamydia and can lead
- to pelvic adhesions.
- Past abdominal surgery
Adhesions, also known as scar tissue, often occur in the pelvic cavity after infections, pelvic surgery or endometriosis. Adhesions can lead to pelvic pain and the possibility of an ectopic pregnancy.
Endometriosis is a condition in which the tissue that lines the uterus develops on other organs inside the pelvis or in the abdominal cavity. Each cycle, this misplaced tissue responds to the hormonal changes resulting in internal bleeding which can affect reproductive organ function.
- Fibroids and polyps in the uterus
- Uterine malformation
- Intrauterine adhesions may be caused by trauma to the uterine cavity, such as dilation and curettage
- The prolonged use of an IUD (intrauterine device) for contraception
- Infections of the endometrium.
Cervix / vaginal problems
Structural abnormalities of the vagina or cervix
The cervical mucus can be hostile to sperm, perhaps containing antibodies or thick enough to block the movement of the sperm.
Abnormal immune response to the pregnancy can lead to pregnancy loss.
Women can also develop antisperm antibodies which attack and destroy sperm.
Low or abnormal sperm function: The vast majority of cases of male infertility are due to a low sperm count, which is generally associated with a high rate of sperm defects (size, shape and movement).
Infections and sexually transmitted diseases: Damage as a result of infections can prevent the sperm from getting into the semen. Occasionally the ejaculate of some men is diverted into the bladder.
Varicocele: Varicocele is a varicose vein around a testicle that may hinder sperm production, movement and shape by raising the testicle´s temperature. Scrotal varicoceles are found in about 15% of males and in approximately 40% of infertile men.
Sperm antibodies: A small group of men actually produce antibodies against their own sperm.
Hormonal disorders do occur in men, but are not very common. They may affect the development of sperm and account for some sperm abnormalities.
Testicular failure: The testes may have been damaged due to a poor blood supply, injury or even a case of adult mumps. Other causes include undescended testes and genetic defects.
Retrograde ejaculation. Retrograde ejaculation involves the ejaculate flowing backward into the bladder instead of leaving the penis.
Erectile dysfunction. Erectile dysfunction is the inability to get or maintain an erection.
Lifestyle and environmental factors
Use of recreational drugs or heavy alcohol, cigarette smoking, certain medications, and excessive heat to the genital area can affect sperm quality and function.
Joint infertility problems
Some of the causes of infertility may be related to the frequency and timing of intercourse.
Frequency: A couple may simply not be having intercourse frequently enough to coincide with the woman’s most fertile phase.
Timing: Equally, the problem could be due to missing the most fertile phase, particularly where the woman’s cycle is not regular, or is longer or shorter than the average 28 days.
Age: Fertility is also reduced with increasing age, especially in women.
What are the risk factors for infertility?
- Age over 35
- Irregular or absent periods
- Two or more miscarriages
- Prior use of an intrauterine device (IUD)
- History of sexually transmitted disease or pelvic/genital infection
- Previous abdominal surgery
- Chronic medical condition (e.g., diabetes, high blood pressure)
- History of sexually transmitted disease or genital infection
- Previous abdominal or urologic surgery
- Chronic medical condition (e.g., diabetes and high blood pressure)
- History of chemotherapy or radiation therapy
- Mumps after puberty
- Family history of genetic disorders
The potential risks of smoking:
- Accelerates the loss of reproductive function and advances the time of menopause
- Increases the risks of spontaneous abortion and ectopic pregnancy
- Increases the risk of pelvic infections
- Is linked to sperm problems in men
Weight and fertility:
Obesity is associated with:
- Decreased fertility
- Irregular or infrequent menstrual cycles
- Increased risk of miscarriage
- Weight loss of 5% to 10% may dramatically improve ovulation and pregnancy rates
- Alcohol consumption has been shown to affect fertility in both men and women.
- Exposure to toxic substances on the job, such as pesticides, radioactivity, x-rays, and electromagnetic or microwave emissions may lead to sperm abnormalities and other health hazards.
- Some drugs for heart disease and high blood pressure may cause infertility in men.