Infertility affects 15% of couples, with male factor infertility contributing to 50% of cases either singly or in combination with female factors. Male fertility issues are most often related to sperm quality and production. Identifying the common medical, lifestyle, and environmental causes of impaired sperm health enables pursuing treatment to improve chances of conception.

Decreased Sperm Production

Low sperm numbers, known as oligospermia, may result from:

• Varicocele – Enlarged veins in the scrotum impairing sperm production
• Undescended testicles – Testes failing to descend into the scrotum during fetal development
• Infections – Gonorrhea, HIV, mumps, TB can damage the testes and epididymis
• Radiation treatment and chemotherapy – For cancer often impairs sperm production
• Trauma or injury to the testicles – From sports, auto accidents, or medical procedures
• Chromosomal defects – Abnormalities like Klinefelter syndrome
• Obesity – Linked to lower testosterone and reduced sperm count
• Heavy metal or toxic exposure – Pesticides, chemicals, drugs, radiation

Abnormal Sperm Shape and Movement

Issues with sperm motility, shape, and function may stem from:

• Antisperm antibodies – The immune system attacks sperm
• Prior infections – Damage to sperm ducts; epididymitis
• Ejaculation issues – Problems with emission or retrograde ejaculation
• Cystic fibrosis gene – Associated with absent vas deferens
• Varicocele – Impairs sperm motility and function
• Uncontrolled diabetes – Glucose buildup damages sperm
• Medications – Steroids, antidepressants, blood pressure drugs
• Overheated testicles – Saunas, tight clothing, hot tubs

Hormonal and Lifestyle Factors

Additional issues negatively impacting sperm and fertility include:

• Low testosterone – Required for sperm production
• High stress levels – Interfere with hormonal balance
• Alcohol and smoking – Shown to reduce sperm count and motility
• Anabolic steroids or testosterone abuse
• Marijuana use – Lowers sperm count and viability
• Advanced paternal age – Declining fertility after 40
• Exposure to toxins – Pesticides, industrial chemicals, heavy metals

Identifying risk factors through a detailed history, examination, and testing allows determining causes and appropriate treatments to improve sperm health and chances of conception.