Antioxidants fail to improve semen quality
Antioxidant supplementation did not improve semen parameters in oligoasthenoteratospermic men, or pregnancy rates in their partners, according to the MOXI* trial presented at ESHRE 2018.
A total of 174 men were randomized to receive a daily antioxidant formulation containing vitamins C, D3, and E, folic acid, zinc, selenium, and L-carnitine for a maximum of 6 months. Participants had low sperm count (oligospermia, ≤15 M/mL, n=66), reduced sperm motility (asthenospermia, ≤40 percent, n=76), and abnormal sperm morphology (teratospermia, ≤4 percent, n=40), as well as higher than normal DNA fragmentation rates (>25 percent). Conception was attempted naturally during the first 3 months, while the ensuing 3 months involved the use of clomiphene citrate with intrauterine insemination in the participants’ female partners. [ESHRE 2018, abstract O-064]
At 3 months, a slight change in sperm concentration was observed between antioxidant and placebo recipients (-4.0 vs +3.2 M/mL; p=0.03). However, no significant between-group difference was observed in terms of morphology, motility, or DNA fragmentation.
Subgroup analysis showed no difference in sperm concentration (8.5 vs 15.0 M/mL; p=0.30), motility (34.0 percent vs 36.3 percent; p=0.93), or morphology (2.0 percent vs 3.0 percent; p=0.28), or DNA fragmentation (28.9 percent vs 28.8 percent; p=0.68).
Cumulative pregnancy rates between the antioxidant and placebo arms did not differ at 3 and 6 months (10.5 percent vs 9.1 percent; p=0.76 and 22.1 percent vs 29.6 percent; p=0.26, respectively).
Despite previous studies showing the positive impact of antioxidants on sperm parameters and pregnancy rates in couples undergoing assisted reproductive technologies, the evidence was limited by small sample sizes, heterogeneity in study samples, antioxidant variety, and nonclinical endpoints, the researchers pointed out.
“[S]permatogenesis and transport together take approximately 74 days, but reactive oxygen species have a greater negative effect during the much shorter sperm transport phase rather than during spermatogenesis. Therefore, antioxidants are thought to have benefit even after a short interval,” said the researchers.
“[Nonetheless, our findings showed that] antioxidants do not appear to improve semen parameters or DNA fragmentation among men with male factor infertility … [and therefore] do not support the empiric use of antioxidant therapy for male factor infertility in couples trying to conceive naturally,” they added.