Does antioxidant supplementation improve subfertility?

This study reviewed if antioxidant supplementation (AOS) improves fertility outcomes. They found that AOS was not associated with better fertility outcomes. 

Infertility is a common condition. It is diagnosed if a couple has not conceived within one year of regular intercourse. Subfertility (SF) is when a couple is fertile but there is a delay in conceiving. Some women with SF undergo fertility treatment. Many may also take supplements to improve fertility outcomes.

Supplementation involves taking vitamins or minerals. Many of these are also antioxidants (AO). AO supplementation (AOS) is popular for general health. AO are compounds that neutralize reactive oxygen species (ROS). ROS can cause DNA damage. This has been linked to reduced fertility. There have been many studies with AOS in subfertile women. However, most studies were small. Therefore, it is unclear if AOS improves fertility outcomes in these women. 

This study included 28 randomized trials on AOS. Overall, 3548 women were included. Some studies compared AOS to placebo. Other studies compared different types of AOS. 

The live birth rate and clinical pregnancy rate (CPR) were similar in AOS and women who received a placebo or no/treatment. One ASO, pentoxifylline (Trental), was associated with a 2-times higher CPR compared to placebo or no treatment. There was no difference between the different types of AOS in this analysis.

Side effects were similar in AOS and placebo groups. 

The authors concluded that AOS was not associated with improved fertility outcomes.

The quality of the evidence analyzed was considered ‘low’ or ‘very low’. This makes it difficult to draw conclusions. More studies are needed to investigate the effect of AOS.