Antioxidant supplementation in men seeking fertility care does not improve pregnancy rates

The use of antioxidant supplements in men seeking fertility care does not appear to increase the chances of conceiving for their female partners, as shown in the multicentre SUMMER trial.

SUMMER included 1,171 men aged 18–50 years (median 34 years) with female partners aged 18–43 years (median 32 years) who sought fertility care and were advised to undergo expectant management, treatment with intrauterine insemination, in vitro fertilization (IVF), or intracytoplasmic sperm injection (ICSI).

The male participants were randomly assigned to receive an antioxidant supplement (n=591) or a placebo (n=591), with one tablet taken daily for 6 months. The antioxidant supplement contained betaine (200 mg), L-cystine (200 mg), niacin (16 mg), zinc (10 mg), vitamin B6 (1.4 mg), vitamin B2 (1.4 mg), folic acid (400 µg), and vitamin B12 (2.5 µg). The placebo tablet and its packaging were identical to those of the antioxidant supplement. All participating couples received standard infertility care.

Ongoing pregnancy conceived within 6 months after randomization was the primary outcome. Secondary outcomes included semen parameters, sperm DNA fragmentation, fertilization and embryo utilization rates after IVF or ICSI, biochemical and clinical pregnancy rates, first-trimester pregnancy loss, ectopic pregnancy rate, cumulative number of pregnancies, time to pregnancy, and adverse events.

The rate of ongoing pregnancy within 6 months did not significantly differ between the antioxidant and placebo groups (33.8 percent vs 37.5 percent; adjusted odds ratio [AOR], 0.85, 95 percent confidence interval [CI], 0.66–1.09; p=0.20).

Within the window of optimal treatment effect between 4 and 6 months (considering a spermatogenesis cycle of 72 days), the rate of ongoing pregnancy was much lower in the antioxidant group than in the placebo group (15.5 percent vs 21.5 percent; AOR, 0.66, 95 percent CI, 0.47–0.94; p=0.02).

Results for the secondary outcomes were similar between the two treatment groups.

The findings do not support the use of antioxidant supplements in men seeking fertility care.