Intended for healthcare professionals

Education And Debate


BMJ 1996; 312 doi: (Published 06 April 1996) Cite this as: BMJ 1996;312:902
  1. Chris Dawson,
  2. Hugh Whitfield


    As many as 15% of couples fail to conceive a child after a year of unprotected intercourse. It is important to investigate both partners fully to evaluate properly where the problem lies. This article considers only the male factors in subfertility.

    Contribution to subfertility

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    Factors in male subfertility

    Men in whom one or both testicles were undescended at birth have lower semen quality than normal, regardless of whether an early orchiopexy was performed. Spermatogenesis can also be impaired if a patient has had testicular pain in childhood or adolescence (signifying an episode of torsion); has had mumps orchitis after puberty; or has used certain prescribed drugs or has misused drugs. As spermatozoa take up to three months to mature fully, seminal analysis may also yield abnormal results for a while if a patient has had a fever.

    Important factors

    • Undescended testes

    • Testicular torsion (and atrophy)

    • Mumps orchitis

    • Drug history/lifestyle

    • Generalised illness

    • Previous surgery

    • Sexual habits

    Several surgical operations may also impair fertility. Retrograde ejaculation may occur in about 40% of men after a bladder neck incision and is even more common after transurethral prostatectomy. The vas deferens and the testicular blood supply may both be damaged during repair of inguinal hernia. Dissection of retroperitoneal lymph nodes may affect the emission and ejaculation of semen by interrupting the sympathetic nervous system.

    Drugs that may inhibit spermatogenesis

    • Alcohol

    • Nicotine

    • Caffeine

    • Marijuana

    Initial assessment

    A general physical inspection will confirm that a patient has normal secondary sexual characteristics. Abnormalities such as hepatomegaly or gynaecomastia may suggest hypogonadism or hormonal abnormalities.

    The testes should be confirmed to lie vertically in the scrotum and be assessed for size and consistency. The vas deferens, reported to be absent in 2% of infertile men, should be carefully palpated. Finally, the patient should stand while the scrotum is examined for the presence of a varicocele.

    Frequency of sexual intercourse

    • The timing and frequency of sexual …

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