Terms oligospermia, oligozoospermia, and low sperm count refer to semen with a low concentration of sperm[1] and is a common finding in male infertility. Often semen with a decreased sperm concentration may also show significant abnormalities in sperm morphology and motility (technically oligoasthenoteratozoospermia). There has been interest in replacing the descriptive terms used in semen analysis with more quantitative information.[2]
The diagnosis of oligozoospermia is based on one low count in a semen analysis performed on two occasions. For many decades sperm concentrations of less than 20 million sperm/ml were considered low or oligospermic, recently, however, the WHO reassessed sperm criteria and established a lower reference point, less than 15 million sperm/ml, consistent with the 5th percentile for fertile men.[3] Sperm concentrations fluctuate daily and oligozoospermia may be temporary or permanent.
The diagnosis of oligozoospermia requires a work-up via semen analysis (listed in Male infertility).
Pre-testicular factors refer to conditions that impede adequate support of the testes and include situations of poor hormonal support and poor general health including:
Mast cells releasing inflammatory mediators appear to directly suppress sperm motility in a potentially reversible manner, and may be a common pathophysiological mechanism for several of the above-mentioned factors.[10]
Post-testicular factors decrease male fertility due to conditions that affect the male genital system after testicular sperm production and include defects of the genital tract as well as problems in ejaculation:
In about 30% of infertile men no causative factor is found for their decrease in sperm concentration or quality by common clinical, instrumental, or laboratory means, and the condition is termed "idiopathic" (unexplained).[11] A number of factors may be involved in the genesis of this condition, including age, infectious agents ( such as Chlamydia trachomatis), Y chromosome microdeletions, mitochondrial changes, environmental pollutants, and "subtle" hormonal changes.[11]
A review in 2013 came to the result that oligospermia and azoospermia are significantly associated with being overweight (odds ratio 1.1), obese (odds ratio 1.3) and morbidly obese (odds ratio 2.0), but the cause of this is unknown.[12] It found no significant relation between oligospermia and being underweight.[12]
Men with mild oligospermia (semen concentration of 15 million to 20 million sperm/ml) were studied for an association of sperm DNA damage with life style factors.[14] A significant association was found between sperm DNA damage and factors such as age, obesity and occupational stress.
Treatment takes place within the context of infertility management and needs also to consider the fecundity of the female partner. Thus the choices can be complex.
In a number of situations direct medical or surgical intervention can improve the sperm concentration, examples are use of FSH in men with pituitary hypogonadism, antibiotics in case of infections, or operative corrections of a hydrocele, varicocele, or vas deferens obstruction.
In most cases of oligospermia including its idiopathic form there is no direct medical or surgical intervention agreed to be effective. Empirically many medical approaches have been tried including clomiphene citrate, tamoxifen, HMG, FSH, HCG, testosterone, Vitamin E, Vitamin C, anti-oxidants, carnitine, acetyl-L-carnitine, zinc, high-protein diets. In a number of pilot studies some positive results have been obtained. Clomiphene citrate has been used with modest success.[15] The combination of tamoxifen plus testosterone was reported to improve the sperm situation.[16]
The use of carnitine showed some promise in a controlled trial in selected cases of male infertility improving sperm quality and further studies are needed.[17]
Achieving a pregnancy naturally may be a challenge if the male has a low sperm count. However, chances are good if the female partner is fertile; many couples with this problem have been successful. Prognosis is more limited if there is a combination of factors that include sperm dysfunction and reduced ovarian reserve.
^thefreedictionary.com > oligospermia Citing: Dorland's Medical Dictionary for Health Consumers, 2007 by Saunders; The American Heritage Medical Dictionary 2007, 2004 by Houghton Mifflin Company; Mosby's Medical Dictionary, 8th edition 2009; McGraw-Hill Concise Dictionary of Modern Medicine, 2002 by The McGraw-Hill Companies
^Grimes DA & Lopez LM 2007 Fertility and Sterility 88(6) 1491-94.
^Leibovitch I, Mor Y (2005). "The vicious cycling: bicycling related urogenital disorders". Eur. Urol. 47 (3): 277–86, discussion 286–7. doi:10.1016/j.eururo.2004.10.024. PMID15716187.
^Costabile RA, Spevak M (2001). "Characterization of patients presenting with male factor infertility in an equal access, no cost medical system". Urology. 58 (6): 1021–4. doi:10.1016/S0090-4295(01)01400-5. PMID11744480.
^Zhoucun A, Zhang S, Yang Y, Ma Y, Zhang W, Lin L (2006). "The common variant N372H in BRCA2 gene may be associated with idiopathic male infertility with azoospermia or severe oligozoospermia". Eur. J. Obstet. Gynecol. Reprod. Biol. 124 (1): 61–4. doi:10.1016/j.ejogrb.2005.09.001. PMID16257105.
^Lenzi A, Lombardo F, Sgro P, Salacone P, Caponecchia L, Dondero F, Gandini L (1991). "Use of carnitine therapy in selected cases of male factor infertility: a double-blind crossover trial". Fertility and Sterility. 25 (5): 1253–326. PMID12569937.
^Sah, P (December 2002). "Oligospermia due to partial maturation arrest responds to low dose estrogen-testosterone combination therapy resulting in live-birth: a case report". Asian Journal of Andrology. 4 (4): 307–8. PMID12508135.