One in 7 couples today would have problems conceiving a child. If female age is often involved, different pathologies can also be at the origin of infertility, whether in men or women, as well as environmental factors or related to lifestyles. Overview.

Female infertility can be schematically classified into 5 major groups:

Ovarian function disorders

 Ovarian function disorders account for about half of female infertility. When they are not related to the patient’s age, they are often due to a disruption of endocrine function (excess or defect in one of the regulators). Concretely, they result in a great difficulty or an inability to produce an oocyte which can be fertilized. Among the pathologies at the origin of ovarian disorders are:

• polycystic ovary syndrome (PCOS),
• multifollicular ovaries,
• macropolycystic ovaries
• anovulation due to a strong source of stress, a strong gain or loss of weight, excessive secretion of prolactin, etc.
• early menopause,
• ovarian failure.

Tubal abnormalities:

 In almost 25% of women with difficulty conceiving, infertility is due to an alteration of the fallopian tubes. Essential to fertilization (it is in the proboscis that the meeting between the oocyte and the spermatozoa takes place), the proboscis can however be damaged, or sometimes even completely blocked, following, in particular, an infection or inflammation. Originally, tubal infertility, various ailments such as:

• pelvic inflammatory disease (PID),
• certain sexually transmitted infections and diseases: salpingitis, chlamydia, etc.
• endometriosis
• bilateral tubal agenesis,
• appendicitis,
• transgenerational in utero exposure to distilbene (DES),
• the consequences of an ectopic pregnancy,
• a history of pelvic surgery, etc.

Uterine factors

 Sometimes the difficulty in procreating is due to a uterine malformation or a problem with the uterine lining (endometrium) that is too thin or even hostile. Congenital or acquired, these uterine factors can in particular prevent the proper implantation of the fetus in the uterine cavity and promote repeated miscarriages. Among them, we frequently find:

• the septate uterus,
• the unicornuate uterus,
• the bicornuate uterus,
• endometrial polyps,
• uterine synechiae,
• fibroids (when they are numerous and large), – certain autoimmune diseases,
• endometritis,
• exposure to DES, etc.

Cervical factors

Female infertility can be caused by an alteration of the cervix and in particular cervical lesions or stenoses. In the event of cervical pathology, the cervix no longer performs its buffer function, thus making fertilization uncertain. The most common cervical causes of infertility:

• polyps,
• endometriosis,
• certain after-effects of surgery or curettage (conization, Asherman’s syndrome),
• exposure to DES, etc.

Genetic factors

Rarer, certain genetic syndromes, like Turner’s syndrome, are accompanied by infertility, as are certain genetic traits (Fragile X syndrome leading to early menopause, for example).

Most male infertility diagnoses can be broadly classified into 2 broad groups:

Disorders of spermatogenesis

Constitutional or acquired, these disorders have one thing in common: an alteration in the quality, quantity and / or mobility of spermatozoa. We then speak of azoospermia (absence of spermatozoa), teratospermia (the shape of the spermatozoa is altered), asthenospermia (in the event of a defect in sperm mobility), or necrospermia (high percentage of dead gametes in the sperm). These disorders can be due to:

• a chromosomal abnormality (Klinefelter syndrome, microdeletions of the Y chromosome, etc.),
• a varicocele,
• cryptorchidism even after surgical management,
• an infection such as mumps (mumps orchitis)
• trauma or lack of blood flow (ischemia) to the testicles, previous surgery (testicular torsion, etc.),
• tumor history,
• pituitary insufficiency (hypogonadism) or other hormonal disorders (hyperprolactinemia, thyroid disease),

Excretory infertility

 In some cases, an alteration of the genital tract prevents sperm from traveling the path necessary for fertilization. These disorders are classified into different families according to their origins.

• In the case ofseminal obstruction which represent 6% of male infertility, we speak of obstructive or excretory azoospermia (or in less serious cases, oligospermia). Here again, these difficulties in conceiving can be present from birth (vesiculo-deferential agenesis, cystic fibrosis, Young’s syndrome, etc.) or acquired following an infection (tuberculosis, chlamydia, etc.) or trauma.
• Post-infectious infertility as their name suggests, are always due to a previous infection, generally urinary or sexually transmitted (urethritis, epididymitis, prostatitis).
• autoimmune infertility: In 8% of infertile men, conception is made difficult due to the formation of anti-sperm autoantibodies. Result: the gametes lose mobility, fertility, tend to agglutinate and migrate poorly in the cervical mucus.
• Ejaculation disorders and disturbances of sexual origin, like retrograde ejaculation, anejaculation or erectile dysfunction. They constitute about 5% of male infertility.

Beyond these specificities linked to sex, certain factors due to lifestyles and environmental exposure are today recognized as disrupting fertility, both in men and women. Among them :

• being overweight or underweight,
• working conditions (prolonged exposure to heat, long transport times),
• the stress,
• lack of sleep,
• tobacco, alcohol, drug use (and coffee for women),
• exposure to pesticides, some of which are known endocrine disruptors,
• exposure to other toxic substances (arsenic, lead, aluminum, mercury, parabens, Bisphenol A),
• intensive sport,
• prolonged exposure to moving waves.