Types of infertility

The following categories of infertility are defined by the World Health Organization (WHO):

• Primary infertility – a complete absence of conception despite regular unprotected sexual intercourse for one year
• Secondary infertility – despite regular unprotected intercourse for a period of one year, a couple is unable to conceive again despite achieving past pregnancy
• Regular spontaneous abortions / infant mortality - mortality of live born infants before reaching one year of age
• Idiopathic (unexplained) infertility - absence of conception caused by other unknown causes or factors, such as lactation, contraception, decreased sex drive, etc.

Causes of infertility

The causes of infertility may differ from one couple to another - mostly these are physical causes in women or men, or combinations thereof. Factors affecting fertility differ in women and men.

The following are the most important factors in women:

• Hormonal problems, e.g. menstrual cycle disorders, anovulation, ovulation disturbances, such as PCOS (polycystic ovarian syndrome), hyperandrogenism (increased levels of male hormones) or hyperprolactinemia (long-term elevated blood prolactin levels) or loss of menstruation after stopping the long-term use of hormonal contraception. Menstrual disturbances occur in very thin women with borderline body weight or women suffering from excessive physical stress (female athletes).
• Endometriosis (the tissue lining the uterine cavity is outside the uterine cavity)
• Damaged or blocked fallopian tubes
• Chromosomal / genetic causes (Turner syndrome)
• Early menopause
• Problems with implantation of a fertilized egg
• Lack of secretion or too thick cervical mucus
• Immunological rejection of sperm (female body produces antibodies against the sperm)

The following are the most important factors in men:

• Decreased semen quality (too few sperm, azoospermia, poor mobility and shape of sperm, unsuccessful sperm-oocyte penetration)
• Chromosomal / genetic causes (Klinefelter syndrome)
• Autoimmunity to sperm antigens (due to inflammation of the testes or epididymis)
• Damaged sperm DNA
• Epididymal or vas deferens blockage (obstruction of the epididymal canal, ejaculation blockage caused by infection)
• Intercourse problems (ejaculation failure, impotence)
• Vasectomy
• Kartagener syndrome
• Drugs affecting sperm quality (chemotherapeutics, anabolic steroids, spironolactone, sulfasalazine)

Other causes leading to impaired fertility

Multiple causes have been reported that may lead to impaired fertility or infertility. Usually, they are related to the contemporary lifestyle with excess stress, overuse of contraception, consumption of medications, drugs and alcohol, or even environmental pollution.

One of the important factors is age, at which a woman decides to conceive a child. The likelihood of conception decreases with age, and declines considerably in women after the age of 30. The eggs decrease in number and quality. Women over 40 years of age have increased rates of spontaneous abortion, ectopic pregnancy, and complications related to pregnancy and childbirth.

It is a good idea to not delay pregnancy :-)