Female Infertility: Causes

Pathogenesis (development of disease)

The pathogenesis of female infertility is complex. In addition to biographical causes, follicle maturation disorders/oocyte maturation disorders (of various etiologies), organic genital as well as extragenital factors are particular causes of the disease.

Etiology (causes)

Biographic causes

  • Genetic burden from mother, grandmothers:
  • Age – decrease in natural fertility – starting from the age of 35:
    • Decrease in the number of eggs: active and dormant follicles decrease with age.
    • Blood flow to the ovaries decreases, which can lead to slower follicle maturation and likewise increased incidence of luteal weakness.
    • Aging of the eggs resulting in chromosomal changes that can lead to failure to fertilize (fertilization) or nidation disorder (implantation disorder) or later lead to miscarriages (miscarriages).
    • Increase in diseases that can be a cause of infertility: Endometriosis (endometrium outside the uterus) and fibroids (benign muscular growths of the uterus), but also chronic diseases that can limit fertility such as thyroid disorders, immunological diseases.
  • Socioeconomic factors
    • Day shift work (fewer mature oocytes (mature eggs) after ovarian hyperstimulation).
    • Occupation with heavy physical work
  • Hormonal factors
    • Ovarian failure – e.g., congenital ovarian failure (failure of ovarian function; = primary ovarian failure).
    • Climacterium praecox (Premature Menopause) – Premature Ovarian Failure (POF) of sister and mother.A woman may enter menopause (menopause) prematurely if egg reserves are depleted prematurely.The average age of onset of menopause is usually circa 51 years. However, if the egg reserves are used up prematurely, ovulation stops (anovulation) and menstruation may also stop prematurely. If this happens in women under the age of 40, it is called a climacterium praecox (premature menopause). A climacterium praecox occurs in 1-4% of women.Attention!If your sister or your mother has premature menopause, it is important to report this to your attending physician, as the occurrence of premature menopause (premature menopause) can be common in a family.
  • Occupations – occupational groups with occupational contact with anesthetic gases.

Behavioral causes

  • Nutrition
    • Malnutrition* – diet that is not complete and low in micronutrients (vital substances).
    • Micronutrient deficiency (vital substances) – see prevention with micronutrients.
  • Consumption of stimulants
    • Alcohol – ≥ 14 alcoholic drinks/week decreased the likelihood of conception by 18%.
    • Coffee* * , black tea
    • Tobacco (smoking)
      • The conception rate (conception rate) was significantly higher in the nonsmoking or occasional smokers than in the heavy smokers (52.2% versus 34.1%), meaning that high tobacco use decreases the receptivity of the endometrium (uterine lining). Furthermore, multiple pregnancies occurred more frequently in the participants who smoked heavily (60% versus 31%).
      • Decreased conception and implantation rates were noted in the transfer of embryos subjectively judged to be morphologically sound in smokers versus nonsmokers.
  • Drug use
    • Cannabis (hashish and marijuana)
    • Et al
  • Physical activity
    • Excessive sports
  • Psycho-social situation
    • Stress
  • Overweight (BMI ≥ 25; obesity* ).
    • BMI > 25 kg/m2 reduces the chance of conception within 1 year (89.4% for BMI 20-25 kg/m2 vs 82.7% for BMI > 25 kg/m2; n = 10 903)
  • Underweight

Attention.* Scientific studies show that approximately 12% of primary infertility is due to severe deviations from normal weight, i.e. overweight or underweight. These weight problems also reduce the prospects of successful infertility treatment.The reason for this is that body fat affects the formation of gonadotropin releasing hormone (GnRH). This triggers the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH), both of which are essential for the development of follicular maturation (egg maturation) and thus for ovulation (ovulation). * * Drinking more than two cups of coffee (160 mg of caffeine) a day can already lead to a poorer fertilization rate. Hormonal disorders – diseases

  • Forms of ovarian insufficiency

    Consequences of ovarian insufficiency:

    • Mild to severe ovarian dysfunction.
    • Corpus luteum insufficiency (luteal weakness).
    • Anovulation (failure to ovulate).
    • Amenorrhea (absence of menstruation).
  • Dysfunction of the: Thyroid (eg latent hypothyroidism), adrenal cortex – resulting in disorders of follicle maturation, that is, egg maturation – and cycle disorders.
  • Polycystic ovary syndrome (PCO syndrome).

Organic (genital) causes

  • Endometriosis – >25% of infertile couples have an unfulfilled desire to have a child due to endometriosis; probably 30-50% of women with endometriosis have an unfulfilled desire to have a child
  • Tubal infertility – tubal occlusion, tubal adhesions, motility disorders (disorders of the ability to move the fallopian tubes)Causes: e.g. because of pelvic inflammatory diseases (PID, Pelvic Inflammatory Disease), adnexitis (inflammation of the fallopian tubes); sexually transmitted diseases (STD, sexually transmitted disease), scarring as a result of surgery or also due to endometriosis (endometrium outside the uterus).
  • Immunological sterility anti-spermatozoa-Ak; ovarian (ovary) auto-antibodies.
  • Uterine (uterus)-related causes of infertility:
    • Uterine malformations – for example, the uterus may be divided into two chambers or have a septum (increased risk of miscarriages)
    • Adenomyosis (adenomyosis uteri) – endometrial islands (uterine lining islands) within the myometrium/uterine muscles (endometriosis uteri).
    • Myoma uteri – (synonym: uterus myomatosus) – enlargement of the uterus due to the presence of one or more myoma nodules (benign muscular growths), which can cause disruption of nidation (implantation of the egg).
    • Adhesions of the endometrium (endometrium) after a surgical procedure on the uterus. Cause: curettage (scraping of the uterus), less frequently after infection (Asherman syndrome: loss of the endometrium due to severe inflammation or trauma (eg, after forced curettage); symptoms: weak to completely absent period bleeding).
    • Positional anomaly of the uterus, which may prolapse into the vaginal canal, that is, into the vagina (this is called prolapse)
  • Tubal sterility – tubal occlusion/occlusion, tubal adhesions (adhesions), tubal motility disorders – Causes: e.g. due to inflammatory (inflammatory) diseases in the pelvic area (PID, Pelvic Inflammatory Disease/ e.g. due toChlamydia trachomatis), adnexitis (ovarian inflammation); sexually transmitted diseases (STD, sexually transmitted disease), scarring due to surgery or also due to endometriosis (occurrence of endometrium (endometrium) extrauterine (outside the uterine cavity)).
  • Vagina (vagina) – malformations; colpitis (vaginitis).
  • Cervical causes of infertility (cervix uteri – cervix).

Disease-related (extragential) causes.

  • Autoimmune diseases – these lead to “autoaggressive digestion”, which means damage to the ovaries (ovaries) can also be the cause of premature menopause.
  • Diabetes mellitus
  • Psychosomatic diseases
    • Anorexia nervosa
    • Bulimia
  • Idiopathic infertility – in about 30% of male cases; in 15% percent of cases, the cause of infertility can not be identified in either the male or female.

Laboratory diagnoses – laboratory parameters that are considered independent risk factors.

  • Hyperprolactinemia (elevated serum prolactin level).
  • Thyroid-stimulating hormone (TSH), although still within normal range, significantly higher than TSH levels of women in the comparison group: twice as many women with unexplained infertility had a TSH level of ≥ 2.5 mIU/l (26.9% vs. 13.5%)

Medications

  • Cytostatics (substances that inhibit cell growth or cell division).

The agents or groups of agents listed below can induce hyperprolactinemia and thus impair follicle maturation (oocyte maturation). This may result in corpus luteum insufficiency (luteal weakness) or, in severe cases, lead to amenorrhea (absence of menstruation for longer than 3 months):

X-rays

Surgeries

  • Operations in the small pelvis – resulting adhesions of the fallopian tubes (tubal sterility).
  • Condition after caesarean section/sectio caesarea (slightly increased risk).

Environmental exposure – intoxications (poisonings).

  • Anaesthetic gases
  • Pesticide-laden foods (→ increase in clinical abortions) versus plant-based diets with low pesticide load (→ decrease in clinical abortions).
  • Triclosan (polychlorinated phenoxyphenol; chlorinated dioxins can be formed from triclosan by exposure to solar radiation, ozone, chlorine and microorganisms); triclosan is contained in disinfectants, toothpaste, deodorants, household cleaners or detergents as well as in textiles and shoes

Other causes

  • Idiopathic infertility – in 15 percent of cases, the cause of infertility can not be identified in either the male or female.