Taking oral antioxidants has been shown to increase fertility in men, but there is no evidence the treatment works for women.
Researchers reviewed data from 28 trials of 3,548 female fertility clinic patients, a University of Auckland press release reported.
"There is no evidence in this review that suggests taking an antioxidant is beneficial for women who are trying to conceive," lead researcher, Marian Showell, of Obstetrics and Gynecology at The University of Auckland, said.
About a quarter of couples trying to conceive experience difficulty, many women undergoing fertility treatments take antioxidants in hopes of increasing their chances of getting pregnant.
The study found women taking antioxidants were no more likely to conceive than those taking placebo pills or folic acid, a standard fertility treatment.
Antioxidant pills are often are largely unregulated, and there have been few studies on side effects and efficiency. The study did not find significant adverse effects as a result of the treatments. Only 14 of the trials experienced miscarriage or ectopic pregnancy.
"I don't think the results were surprising in the sense that there are no national organizations or guidelines that recommend routine use of antioxidant supplements for fertility," Dr. Wendy Vitek, head of the fertility preservation program at the University of Rochester's Strong Fertility Center, who did not participate in the study, said,the Huffington Post reported.
"But I definitely have women ask me about supplements. I think there are a lot of feelings of self-blame with infertility, and women are looking to gain some sense of being proactive and of potentially controlling a very uncontrollable situation," she said.
Some of the treatments classified as "antioxidants" include: Melatonin, Calcium, Omega-3 polyunsaturated fatty acids, and vitamins C, D, and E, Medical News Today reported.
A past study found antioxidant use could improve fertility in male partners, but said further testing would needed in order to confirm the finding.
Researchers believe the treatments help "improve sperm quality by reducing oxidative stress."
Oxidative stress occurs when free radicals attack cells, impairing their ability to function. Medical researchers had reasoned the antioxidant treatments could have a similar outcome in females.
"It is thought that the free radical 'scavenging' effects of antioxidants would help to repair any oxidative stress occurring in the female reproductive process," Showell, said. "This has not been disproven by this review. We just didn't have high enough quality evidence to prove or disprove it."
