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This article waslast modified on 26 September 2023.
What is infertility?

Infertility is a condition or disease affecting the reproductive system that prevents successful pregnancy. It is typically diagnosed after a couple has had 12 months or regular (every 2-3 days) of unprotected, well-timed (around the time of ovulation) intercourse without a pregnancy occurring or when a woman has been unable to carry a pregnancy that results in a live birth.

Problems in fertility can occur at any point in the process of conception – in the development or release of the egg or sperm, in fertilisation or transport of the fertilised egg from the fallopian tube to the uterus, in implantation of the embryo in the uterine lining (the endometrium), even in the timing of intercourse or physical conditions after conception. In the female, the reproductive system consists of the vagina, cervix, uterus, fallopian tubes, ovaries, and vulva (the external structures). The male genital organs include the testicles, vas deferens, seminal vesicles, prostate gland, and penis. Hormones controlling reproduction and metabolism (produced by the hypothalamus, pituitary, and thyroid glands as well as the ovaries and testes) also play an important role.

In the UK approximately 1 in 7 couples have impaired fertility. The source of the infertility problem may be in either partner. Age can play an important role ― especially in women, but also in men. Endometriosis and the effects of sexually transmitted diseases may be factors in infertility. The presence of other diseases or infection in either partner can be a source of the problem. Nutritional, health, lifestyle choices, and environmental factors also have an effect. The most common defects reported are sperm disorders in men, and damaged or blocked tubes or ovulation problems in women. No cause is identified in up to one third of cases.

Risk factors for infertility include smoking, obesity, occupational risks, excessive alcohol and drug use. Psychological stress in either party may also contribute.

Infertility testing can be complex, expensive, and time-consuming. Often, both partners are required to undergo history taking, extensive physical examinations, blood tests, evaluation of lifestyles, and/or ultrasound testing to determine the source of the problem.


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About Infertility
  • Tests of Female Fertility

    A woman’s fertility declines substantially by age 35 and even more so after age 40. Infertility occurs because an egg may not be produced, or once released, it may not get to the womb, sperm may not reach it, or a fertilised egg may fail to develop. Common reasons for female infertility include blocked fallopian tubes, polycystic ovary syndrome (PCOS interferes with egg release), fibroids, Endometriosis, autoimmune disorders (producing antibodies against fetal tissue), diabetes, hypothyroidism, eating disorders, excessive smoking and alcohol intake, extreme exercise, and gluten intolerance (coeliac disease). A woman’s fertility may also be affected by factors such as fluctuating or diminished hormone levels; inconsistent ovulation; or a poor reproductive environment that does not support proper fertilisation of the egg, interferes with the sperm’s transport, or impairs retention of a fertilised egg.

    The initial evaluation of a woman’s fertility includes a personal and family history with a thorough physical examination. A number of tests can be used to help diagnose the problem and aid in treatment.

    Initial investigations may include some blood tests, such as measuring the levels of hormones involved in reproduction: mid-luteal luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), oestradiol, and progesterone. Other measurements which can help include thyroid function tests (TSH and/or T4) and steriods such as  testosterone and DHEA-S (dehydroepiandrosterone sulphate is used in creating androgens and oestrogens). These tests help to check the health of the pituitary, thyroid and adrenal glands which can themselves affect the menstrual cycle and ovulation. Further investigations may be undertaken in specialist clinics and may include additional blood tests such as anti-Müllerian hormone (AMH) to assess ovarian reserve, or imaging techniques such as ultrasound (US) to look at individual reproductive organs.

    Screening for Chlamydia infection (an infection which can cause pelvic inflammatory disease, a cause of infertility) may also be requested.

  • Tests of Male Fertility

    A man’s fertility can be affected by factors such as a low sperm count, poor sperm movement (motility), clumped (or agglutinated) sperm (unable to swim to the egg), abnormally shaped sperm, enlarged veins around the testes (varicoceles), obstructions that prevent sperm from being released during ejaculation, and genetic or congenital conditions that impair the reproductive environment. The most common anatomic abnormality in men is varicoceles.

    A history of having mumps, testicular injury, exposure to chemicals or toxins, acute illness or prolonged fever, drug or alcohol use, and ingestion of anabolic steroids can negatively impact male fertility. Temperature also affects sperm efficiency. Age-related problems include decreased testosterone production; declining sperm mobility or production; prostate, erectile, or ejaculation problems; and excessive alcohol use.

    For the male, a medical history and physical examination to detect anatomic abnormalities may be all that is necessary to diagnose an infertility problem.

    Semen analysis. Semen analysis is the mainstay of male testing. Collection and prompt evaluation of an ejaculate can quickly determine any abnormalities in the number of sperm, their shape, and ability to swim toward the egg.

    Blood tests. Measurements of the levels of some hormones in blood may contribute to understanding in male reproductive disorders: testosterone, luteinising hormone (LH), follicle-stimulating hormone (FSH), and prolactin (PRL).

    In some instances a biopsy of testicular tissue may be required to identify the problem.

    Screening for Chlamydia infection also takes place.

  • Treatment

    A fertility treatment plan, involving both the man and woman, may include changes to lifestyle, and to environmental factors. Drug therapies such as clomifene (to induce ovulation), hormone therapy, surgical intervention, and assisted reproduction techniques may be used, depending on the problem and diagnosis. Such treatment is undertaken in specialist clinics.