Antioxidant supplementation does not effectively increase rates of live birth or clinical pregnancy in subfertile women, according to a review published online in The Cochrane Library.
Marian G. Showell, M.P.H., from the University of Auckland in New Zealand, and colleagues conducted a literature review and identified 28 randomized controlled trials involving 3,548 women to examine whether supplementary oral antioxidants improve fertility outcomes for subfertile women. The trials compared any type, dose, or combination of oral antioxidant supplement with placebo, no treatment, or treatment with another antioxidant in women attending reproductive clinics.
The researchers found that the overall quality of evidence was very-low to low. Based on two trials involving 97 women, compared with placebo or no treatment/standard treatment, antioxidants were not associated with an increased live birth rate (odds ratio [OR], 1.25; P = 0.82; I², 75 percent). Based on 13 trials involving 2,441 women, compared with placebo or no treatment/standard treatment, antioxidants were not associated with an increased clinical pregnancy rate (OR, 1.30; P = 0.14; I², 55 percent). Based on three trials involving 276 women, there was a significantly increased clinical pregnancy rate seen with pentoxifylline versus placebo or no treatment (OR 2.03; P = 0.009; I², 0 percent). Although the data were limited, there was no evidence of differences in adverse effects between antioxidant groups and control groups.
“The quality of the evidence in the ‘antioxidant versus placebo/no treatment’ and in the ‘antioxidant versus antioxidant’ comparisons was assessed to be ‘very low,'” the authors write .