Semen analysis is used to examine the quantity and quality of semen and sperm. It assesses for male factor infertility.
Providing a Sample
Men should be given clear instructions for providing a sample:
- Abstain from ejaculation for at least 3 days and at most 7 days
- Avoid hot baths, sauna and tight underwear during the lead up to providing a sample
- Attempt to catch the full sample
- Deliver the sample to the lab within 1 hour of ejaculation
- Keep the sample warm (e.g. in underwear) before delivery
Factors Affecting Semen Analysis and Sperm Quality and Quantity
Several lifestyle factors may affect the results of semen analysis and the quality and quantity of sperm:
- Hot baths
- Tight underwear
- Smoking
- Alcohol
- Raised BMI
- Caffeine
A repeat sample is indicated after 3 months in borderline results or earlier (2 – 4 weeks) with very abnormal results.
Results
Normal results indicated by the World Health Organisation are:
- Semen volume (more than 1.5ml)
- Semen pH (greater than 7.2)
- Concentration of sperm (more than 15 million per ml)
- Total number of sperm (more than 39 million per sample)
- Motility of sperm (more than 40% of sperm are mobile)
- Vitality of sperm (more than 58% of sperm are active)
- Percentage of normal sperm (more than 4%)
Polyspermia (or polyzoospermia) refers to a high number of sperm in the semen sample (more than 250 million per ml).
Normospermia (or normozoospermia) refers to normal characteristics of the sperm in the semen sample.
Oligospermia (or oligozoospermia) is a reduced number of sperm in the semen sample. It is classified as:
- Mild oligospermia (10 to 15 million / ml)
- Moderate oligospermia (5 to 10 million / ml)
- Severe oligospermia (less than 5 million / ml)
Cryptozoospermia refers to very few sperm in the semen sample (less than 1 million / ml).
Azoospermia is the absence of sperm in the semen.
Pre-Testicular Causes
Testosterone is necessary for sperm creation. The hypothalamo-pituitary-gonadal axis controls testosterone. Hypogonadotrophic hypogonadism (low LH and FSH resulting in low testosterone), can be due to:
- Pathology of the pituitary gland or hypothalamus
- Suppression due to stress, chronic conditions or hyperprolactinaemia
- Kallman syndrome
Testicular Causes
Testicular damage from:
- Mumps
- Undescended testes
- Trauma
- Radiotherapy
- Chemotherapy
- Cancer
Genetic or congenital disorders that result in defective or absent sperm production, such as:
- Klinefelter syndrome
- Y chromosome deletions
- Sertoli cell-only syndrome
- Anorchia (absent testes)
Post-Testicular Causes
Obstruction preventing sperm being ejaculated can be caused by:
- Damage to the testicle or vas deferens from trauma, surgery or cancer
- Ejaculatory duct obstruction
- Retrograde ejaculation
- Scarring from epididymitis, for example, caused by chlamydia
- Absence of the vas deferens (may be associated with cystic fibrosis)
- Young’s syndrome (obstructive azoospermia, bronchiectasis and rhinosinusitis)
Investigations
The initial steps for investigating abnormal semen analysis include a history, examination, repeat sample and ultrasound of the testes.
Patients with abnormal semen results are referred to a urologist for further investigations. Further investigations that may be considered include:
- Hormonal analysis with LH, FSH and testosterone levels
- Genetic testing
- Further imaging, such as transrectal ultrasound or MRI
- Vasography, which involves injecting contrast into the vas deferens and performing xray to assess for obstruction
- Testicular biopsy
Management
Management depends on the underlying cause, and can involve:
- Surgical sperm retrieval where there is obstruction
- Surgical correction of an obstruction in the vas deferens
- Intra-uterine insemination involves separating high-quality sperm, then injecting them into the uterus
- Intracytoplasmic sperm injection (ICSI) involves injecting sperm directly into the cytoplasm of an egg
- Donor insemination involves sperm from a donor
Last updated August 2020