What is teratozoospermia and how is it treated?

Teratozoospermia: Diagnosis and Management

Teratozoospermia is a condition characterized by an abnormally high percentage of morphologically abnormal sperm in semen, which can significantly impact male fertility and should be evaluated by a male reproductive expert for complete history, physical examination, and directed tests. 1

Definition and Diagnosis

• Teratozoospermia is diagnosed when there is an abnormally high percentage of morphologically abnormal sperm in the semen
• According to WHO criteria, normal sperm morphology should be present in at least 4% of sperm
• At least two semen analyses obtained a month apart should be considered for diagnosis, as semen parameters can fluctuate substantially between tests 2

Types of Teratozoospermia

1. Polymorphic teratozoospermia: Most common form where majority of spermatozoa display more than one type of abnormality 3

2. Monomorphic teratozoospermia: Represents less than 1% of male infertility cases, with two main forms 4:

   • Globozoospermia (round-headed sperm syndrome): Characterized by round spermatic heads, absence of acrosome, and disorganization of mid-piece and tail
   • Macrozoospermia (macrocephalic sperm head syndrome): Characterized by enlarged sperm heads and multiple flagella

Evaluation

Men with teratozoospermia should undergo:

1. Complete reproductive history 1
2. Physical examination to assess:
   • Testicular size and consistency
   • Presence of varicocele
   • Signs of hypogonadism
   • Examination of epididymides and vas deferens 2
3. Laboratory testing:
   • Hormonal evaluation including FSH, LH, and testosterone 1, 2
   • Genetic testing for men with severe teratozoospermia, including:
     • Karyotype analysis
     • Y-chromosome microdeletion testing 1
   • Sperm DNA fragmentation testing in cases of recurrent pregnancy loss 1

Causes

1. Genetic factors:

   • Chromosomal abnormalities 3
   • Gene mutations (AURKC gene in macrozoospermia; SPATA16, PICK1, and DPY19L2 genes in globozoospermia) 4

2. Environmental and lifestyle factors:

   • Obesity
   • Smoking
   • Excessive heat exposure
   • Exposure to toxins 2, 5

3. Medical conditions:

   • Varicocele
   • Infections (may be associated with asthenozoospermia and teratozoospermia) 6
   • Hormonal imbalances 2

Clinical Significance

• Men with teratozoospermia have higher rates of:

  • Sperm DNA fragmentation
  • Elevated oxidative stress
  • Low antioxidant function
  • Apoptotic alterations 5

• The impact on fertility varies by type:

  • Polymorphic teratozoospermia: Slight increase in aneuploidy frequency 3
  • Globozoospermia: Moderate increase in aneuploidy frequency for acrocentrics and sex chromosomes 3
  • Macrozoospermia: Very high level of chromosomal abnormalities (nearly 100% aneuploidy) 3

Treatment Approaches

1. Address underlying causes:

   • Lifestyle modifications (weight loss, smoking cessation, avoiding excessive heat exposure) 2
   • Treatment of varicocele if present 5
   • Management of infections with appropriate antibiotics 6

2. Empiric medical therapy:

   • Antioxidant supplementation (vitamin C, vitamin E, coenzyme Q10) may be beneficial, though evidence is limited 2

3. Assisted reproductive technologies:

   • For polymorphic teratozoospermia and mild cases: Intrauterine insemination (IUI) may be effective 5
   • For moderate cases: Intracytoplasmic sperm injection (ICSI) is often recommended 3
   • For macrozoospermia with high aneuploidy rates: ICSI should be avoided; sperm donation should be considered 3

4. Genetic counseling:

   • Essential before assisted reproduction for men with genetic abnormalities 2
   • Particularly important for cases of monomorphic teratozoospermia with identified genetic mutations 4

Prognosis

• Fertility outcomes vary significantly based on:

  • Type and severity of teratozoospermia
  • Associated sperm abnormalities (count, motility)
  • Presence of genetic factors

• Recent meta-analyses suggest isolated teratozoospermia (with normal count and motility) may not be associated with poor fertility outcomes from assisted reproductive technologies 5

Important Considerations

• Men with abnormal semen parameters have higher rates of testicular cancer and general cancer than fertile men 1
• Mortality rates have been positively associated with abnormal semen analyses 1
• Comprehensive health assessment is important as men with teratozoospermia may have higher risk of metabolic syndrome 2