Medical specialists sometimes refer to failure to conceive within a year as an 'unfulfilled desire to have children.' It is however possible for spontaneous pregnancy to occur after a period of two or more years.

Failure to conceive can have numerous causes. In most cases, the underlying cause is not sterility, but a fertility disorder of varying seriousness. In general, a third of fertility disorders are attributed to women, a third to men and a third to both partners. Psychological factors are only rarely the cause of an inability to have children.

This basal temperature method can also be supported by the use of a 'cycle computer' - also used for contraception. Some cycle computers even can determine the time of ovulation, based on the hormone levels in your urine.

Hormone testing, with ultrasound
This ascertains whether or not ovulation is occurring regularly by ruling out hormonal/functional disorders of the ovaries.

Contract sonography or ultrasound
Investigates possible damage or problems in the fallopian tubes

Performed in the laboratory to determine the composition and motility of sperm cells and the sperm count in male semen.

In cases where fertility disorders have more serious causes, the female repdocutive organs can be examined by means of an abdominal endoscopy (laparoscopy) and a uterine endoscopy (hysteroscopy). These procedures are referred to as "micro invasive" surgery.