Supplement use among couples seeking fertility treatment and associations with live birth and pregnancy loss

Objective: To assess the supplement use patterns among couples seeking fertility treatment and to assess the association between supplement use and live birth and pregnancy loss. Design: A secondary analysis using Folic Acid and Zinc Supplementation Trial (FAZST) and Impact of Diet, Exercise, and Lifestyle on Fertility Study (IDEAL) of couples seeking fertility treatment, followed for ≤18 months. Subjects: Couples seeking fertility treatment. Exposure: Multivitamin and five most common supplements used among females (calcium, fish oil, folic acid, vitamin B12, vitamin C) and males (coenzyme Q10, fish oil, vitamin B12, vitamin C, and zinc) collected at baseline. Main Outcome Measures: Live birth and pregnancy loss were ascertained via self-report and medical records. Poisson models with robust variance estimates were used to estimate risk ratios (RR) and 95% confidence intervals (CI), adjusting for confounders and weighted for selection bias. Results: Among 2,370 couples, 37% of males and 67% of females used a multivitamin at baseline. Overall, 35% of couples achieved a live birth. Multivitamin use in female (adjusted risk ratio [aRR] = 1.22; 95% CI: 1.05–1.41), but not the male (aRR = 1.00; 95% CI: 0.89–1.12) partner, was associated with an increased chance of live birth. When stratified by fertility treatment, female multivitamin use was associated with live birth only among partners who underwent no treatment (aRR = 1.44; 95% CI: 1.00–2.08). Among females, folic acid (aRR = 1.18; 0.95–1.48) and fish oil (aRR = 1.09; 95% CI: 0.86–1.36) showed no live-birth association; males showed null findings for fish oil and vitamin C. 1054 (44%) conceived and of those, 218 (21%) had a pregnancy loss. There was no association between multivitamin use in either partner and pregnancy loss. Conclusion: Among couples seeking infertility treatment, supplement use was common among both female and male partners, with the majority taking a multivitamin. There was evidence that multivitamin use in female partners was associated with increased likelihood of live birth.