Causes Of Infertility
Approximately 20 per cent of couples experience difficulties in conceiving. In most cases, the couple can be helped with assisted reproductive technologies.
Causes Of Male Infertility
Around 40 per cent of fertility problems originate in the man. The most common causes of male infertility include:
- Sperm production, function or delivery including undescended testicles (one or both testicles are missing from the scrotum and are lodged instead in the groin or inside the lower abdomen) , endocrine functions, accessory gland function, genetic defects, repeated infections, sexual difficulties, premature ejaculation, and blockage of the part of the testicle that contains sperm (epididymis).
- Other health issues can also impact on male fertility such as certain genetic diseases, including cystic fibrosis. Cancer and its treatment can also cause infertility. Both radiation and chemotherapy treatment for cancer can impair sperm production.
- Health and lifestyle, including poor nutrition, obesity, or excessive use of alcohol, tobacco and drugs. Please go to our Increasing Your Chances Of A Pregnancy page for further information.
- Overexposure to certain environmental factors, such as pesticides and other chemicals. This may impair sperm production and lower the sperm count. Please go to our Increasing Your Chances Of A Pregnancy page for further information.
- Age. There is a decrease in fertility as men age and an increased risk of genetic defects. A study has shown that men aged 40 years having intercourse twice per week will have approximately 10% lower cumulative success rates compared with men aged 35 years over a period up to 24 months (Dunson, DB. Baird, DD. Colombo, B. Increased infertility with age in men and women. Obstet Gynecol 103, 51–56).
- Unexplained infertility where standard fertility tests have not found the cause of the fertility issue.
Investigating suspected male infertility may require a number of tests.
There are currently no treatments available that can improve the quality of a man’s sperm. However, options are available that can increase the odds of conception using the existing sperm quality. Treatment options depend on your clinical profile and personal preferences, but may include:
- Intrauterine Insemination (IUI).
- In Vitro Fertilisation (IVF) And Intracytoplasmic Sperm Injection (ICSI).
- Testicular Sperm Aspiration or Microsurgical Sperm Retrival.
For further helpful information about male infertility, please visit the Andrology Australia website.
Causes Of Female Infertility
Around 40 per cent of fertility problems originate in the woman. The most common causes of female infertility include:
- Fallopian tube damage or blockage, which can result from inflammation of the fallopian tube (salpingitis). Chlamydia, a sexually transmitted infection, is a frequent cause.
- Endometriosis is a condition in which cells from the lining of the uterus (the endometrium) are found outside of the uterus and can cause pain and infertility. Endometriosis has an estimated prevalence of 0.5-5% in fertile and 25-40% in infertile women (NICE Guidelines. Fertility: assessment and treatment for people with fertility problems (update). Draft for stakeholder consultation – May 2012).
- Ovulation disorders, can prevent the ovaries from releasing eggs (anovulation). The most common symptoms are infrequent or absent menstrual periods. Underlying causes may include hormonal imbalances, eating disorders and excessive exercise. In addition, some medications and recreational drugs can be associated with ovulation disorders. Ovulation disorders are the cause of subfertility in around 25% of couples who have difficulty conceiving (NICE Guidelines. Fertility: assessment and treatment for people with fertility problems (update). Draft for stakeholder consultation – May 2012).
- Elevated prolactin (hyperprolactinemia), the hormone that stimulates breast milk production. High levels in women may affect ovulation.
- Polycystic ovary syndrome (PCOS) is a condition in which a woman has an imbalance of female sex hormones that may lead to menstrual cycle changes, cysts in the ovaries, trouble getting pregnant, and other health changes. At the time of ovulation, the ovaries produce small cysts and typically, one follicle ripens to release an egg. In PCOS, the follicles fail to ripen, forming multiple small cysts. PCOS affects between 12-18% of women of reproductive age.
- Early menopause is the absence of menstruation and the early depletion of ovarian follicles before age 40. Early menopause can be caused by certain medical treatments, or it can just happen on its own. Medical treatments that may cause early menopause include chemotherapy or pelvic radiation treatments for cancer, and surgery to remove the ovaries. Other causes include chromosome defects, autoimmune diseases, and unexplained causes.
- Uterine fibroids are benign tumors in the wall of the uterus and are common in women in their 30s and 40s. Rarely, they may cause infertility by blocking the fallopian tubes. More often, fibroids interfere with proper implantation of the embryo.
- Pelvic adhesions, bands of scar tissue that bind organs after pelvic infection, appendicitis, or abdominal or pelvic surgery and fertility. This scar tissue formation may impair tubal transport of the egg into the tube.
- Health and lifestyle issues, Lifestyle factors that may affect the chance of conception and a healthy live birth include weight, diet, exercise, vitamin intake, smoking, caffeine and alcohol intake, recreational drugs and environmental pollutants. For example - there is evidence that male and female fertility is decreased when individuals are over or underweight. There is also a significant association between smoking and reduced fertility in both males and females (including passive smoking). The use of recreational drugs or drugs of abuse such as marijuana and cocaine can adversely affect ovulatory and tubal function. While the evidence is inconsistent there may be an association between high levels of caffeine and fertility problems and alcohol consumption has also been associated with reduced fertility. Please go to our Increasing Your Chances Of A Pregnancy page for further information.
- Age. As women age their fertility and the chance of becoming pregnant is reduced because the quality and number of eggs decreases. This becomes significant after the age of 32 with a gradual decrease in the chance of conceiving and an increase in the chance of pregnancy complications.
- Unexplained infertility means standard fertility tests have not found the cause of the infertility issue.
Other causes in women
- Medications. Temporary infertility may occur with the use of certain medications.
- Thyroid problems. Disorders of the thyroid gland, either too much hormone (hyperthyroidism) or too little (hypothyroidism), can interrupt the menstrual cycle and cause infertility.
- Cancer and its treatment. Certain cancers - particularly female reproductive cancers can severely impair female fertility. Radiation, chemotherapy and surgery to the reproductive tract may affect a woman's ability to reproduce. Chemotherapy may impair reproductive function and fertility in men and women.
Investigating suspected female infertility may require a number of tests.
Treatment options depend on your clinical profile and personal preferences, but may include:
- Tubal And Uterine Surgery.
- Assisted reproductive treatment, for example, In Vitro Fertilisation (IVF).
- Polycystic Ovary Syndrome Management (PCOS).
- Intrauterine Insemination (IUI).
- Ovulation Induction (OI).
- Medical And Surgical Management Of Endometriosis.