Antioxidants for male subfertility.
BACKGROUND
Between 30% to 80% of male subfertility cases are considered to be due to the damaging effects of oxidative stress on sperm. Oral supplementation with antioxidants may improve sperm quality by reducing oxidative stress.


OBJECTIVE
This Cochrane review aimed to evaluate the effect of oral supplementation with antioxidants for male partners of couples undergoing assisted reproduction techniques (ART).


METHODS
We searched the Cochrane Menstrual Disorders and Subfertility Group Register, CENTRAL (The Cochrane Library), MEDLINE, EMBASE, CINAHL, PsycINFO and AMED databases (from their inception until Febuary 2010), trial registers, sources of unpublished literature, reference lists and we asked experts in the field.


METHODS
We included randomised controlled trials comparing any type or dose of antioxidant supplement (single or combined) taken by the male partner of a couple seeking fertility assistance with placebo, no treatment or another antioxidant. The outcomes were live birth, pregnancy, miscarriage, stillbirth, sperm DNA damage, sperm motility, sperm concentration and adverse effects.


METHODS
Two review authors independently assessed studies for inclusion and trial quality, and extracted data.


RESULTS
We included 34 trials with 2876 couples in total. Live birth: three trials reported live birth. Men taking oral antioxidants had an associated statistically significant increase in live birth rate (pooled odds ratio (OR) 4.85, 95% CI 1.92 to 12.24; P = 0.0008, I(2) = 0%) when compared with the men taking the control. This result was based on 20 live births from a total of 214 couples in only three studies.Pregnancy rate: there were 96 pregnancies in 15 trials including 964 couples. Antioxidant use was associated with a statistically significant increased pregnancy rate compared to control (pooled OR 4.18, 95% CI 2.65 to 6.59; P < 0.00001, I(2) = 0%).Side effects: no studies reported evidence of harmful side effects of the antioxidant therapy used.


CONCLUSIONS
The evidence suggests that antioxidant supplementation in subfertile males may improve the outcomes of live birth and pregnancy rate for subfertile couples undergoing ART cycles. Further head to head comparisons are necessary to identify the superiority of one antioxidant over another.
Obstetrics and Gynaecology, University of Auckland, Park Road Grafton, Auckland, New Zealand.
Marian G
MG
Showell
Julie
J
Brown
Anusch
A
Yazdani
Marcin T
MT
Stankiewicz
Roger J
RJ
Hart
D000975:Antioxidants / Q000627:therapeutic use*; D004249:DNA Damage; D005260:Female; D006801:Humans; D007248:Infertility, Male / Q000188:drug therapy* / Q000209:etiology; D050498:Live Birth; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D011247:Pregnancy; D018873:Pregnancy Rate; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects
D000975:Antioxidants