Infertility is defined as the failure to achieve a pregnancy after one year of regular (at least twice weekly) unprotected intercourse with the same female partner. Male infertility is diagnosed after testing has been performed on both partners and reproductive problems have been identified in the male partner. One in six couples in Australia have difficulty becoming pregnant and is considered infertile. In approximately one in five infertile couples the problem lies solely in the male partner (male infertility). Male infertility is the underlying reason for 40% of infertile couples using assisted reproduction technologies. In most cases, there are no obvious signs of an infertility problem. Intercourse, erections and ejaculation will usually happen without difficulty. The quantity and appearance of the ejaculated semen can appear normal to the naked eye. The initial screening evaluation of the male partner includes a history and two properly performed semen analyses. If abnormalities are revealed by either the history or analyses, the male partner should be further evaluated. Some known causes of male infertility include:
Sperm production problems:
Approximately two thirds of infertile males have sperm production problems. Low numbers of sperm are made and/or the sperm that are made do not function properly. A number of factors can disrupt the production of sperm including undescended testis, infections such as mumps, heat, sperm antibodies, drugs or radiation damage.
Blockage (obstruction) of sperm transport:
An obstruction is the second most common cause of male infertility and affects about three in every 20 infertile men, including men with the common problem of having an earlier vasectomy. An obstruction in the tubes that carry sperm away from the testes to the penis can cause a complete lack of sperm in the ejaculated semen.
In some men, sperm antibodies can develop which can lessen sperm movement and block egg binding during fertilisation. About one in every 16 infertile men has sperm antibodies.
Difficulties with sexual intercourse, such as erection or ejaculation problems, can also reduce the chance of becoming pregnant. Nerve damage following spinal cord injury, diabetes, or surgery to the prostate or pelvis can impact erection and ejaculation. Some drugs to treat depression or high blood pressure may also cause erection and ejaculation problems. Sexual problems are not a common cause of infertility and affect less than one in 100 infertile men.
Sometimes the pituitary gland, located behind the nose, underneath the brain, does not send the right messages to the testes. This can cause low testosterone levels, which means that sperm are not produced. Hormonal causes are uncommon and affect less than one in 100 infertile men. Anabolic (androgenic) steroid abuse by body builders can shut off the hormones from the pituitary gland and lead to a low sperm count. In no situation do we ever recommend that fertility diagnosis or treatment be undertaken without the guidance of a qualified medical practitioner.