• Sexually transmitted infections:
• Neisseria gonorrhoea, Chlamydia trachomatis, TPHA, RPR;
• HBsAg, anti – HBc, anti – HCV, anti – HIV.
• Hormonal tests.

FSH, LH, testosterone, TSH and prolactin serum levels for men with suspected endocrinopathy or pathological spermogram (e.g., severe oligospermia).

• Transrectal ultrasonography to diagnose ejaculatory obstruction (patients with azoospermia and small ejaculate volume).
• Testicular ultrasound is performed if there is difficulty in the inspection and palpation or suspected testicular tumour.
• Testicular biopsy.
• Testicular biopsy is taken for diagnostic purposes in patients with an uncertain cause of azoospermia, when testicular volume and serum FSH levels are normal.
• Testicular biopsy in patients with reduced testicular volume and elevated FSH levels in cases when an IVF procedure is planned or to rule out a testicle tumour (altered oncological testing).
• Genetic testing.

Indications for genetic consultation and examination are azoospermia, severe oligospermia, or congenital lack of the vas deferens.