Causes of Male Factor Infertility

There are several causes of male factor infertility: genetic, hormonal, varicocele, infection, anatomical malformations, chemical insult, idiopathic oligospermia accounts for 30%. Below we are going to explore several factors:

Genetic Factors

  • Chromosomal abnormality can be found in about 15% of azoospermic men and 6% of
    men with severe oligospermia.
  • Klinefelter syndrome (47XXY)
    – Nondisjunction in meiosis 1 or 2
  • Congenital absence of the vas deferens
  • Kallman’s syndrome-genetic condition that results in hypogonadotropic hypogonadism
    (and inability to smell)

Y Chromosome Microdeletion

  • Missing gene(s) in the long arm of the Y chromosome that are associated with
    spermatogenesis
  • May not have any symptoms but reduced fertility
  • Prevalence about 7%

Factors Affecting Spermatogenesis

  • Stress
  • Age
  • Toxins (lead, plastics, tobacco, ETOH, cannabis)
  • Exposure to radiation or chemo
  • Prolactinoma
  • Cryptorchidism (absence of one or both testes from the scrotum) usually undescended and will descend by first year of life.
  • Infections:
    – Mumps, chickenpox, STDs
    – Can cause orchitis (testicle infection)
    – Prostatitis
  • Heat- hot tubs, sauna, long distance running, biking, truck drivers, tight underwear

Varicocele

  • 35% of subfertile men
  • Lower sperm count and quality
  • Lower sperm function
  • Elevated oxidative stress-elevated sperm DNA damage

*Miyaoka & Esteves, Adv Urol 2012; Agarwal, Esteves, Hamada; Nature Urol Rev 2013

Varicocele Repair

  • Varicocelectomy
    – Done under microscopic guidance might improve outcome
    – Wait around 6 months to resume treatment
    – 60-70% show improvement
    – 40-50% pregnancy rate

ASRM Practice Guideline- Varicocele Tx

  • Indications for varicocele repair
    – Infertile couples
    – Normal female or treatable female infertility
    – Abnormal S/A or sperm function test
  • Some studies have shown that treating the varicocele prior to ICSI can increase # of fertile eggs, live birth % and miscarriage rate (Esteves, SC et al, journal of urology vol 184: 1442-6, 2010)
  • Probability of semen improvement: 50-70%

Male Obesity

  • Increases risk of hypogonadotropic/hypogonadism (leptin alters GnRH)
  • Is risk factor for subfertility
  • Negative correlation between elevated BMI, Total and Free T
  • Oligo- and Asthenospermia increase with increasing BMI
  • Decreases sperm, embryo quality and placental development
  • In animal study, rate of embryo implantation and fetal development decreased in mice with obese fathers by up to 15%*.

*Binder, et al. 2012. Abstract presented at ESA-SRB

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