Association of male fatty acid intake with fecundability among couples planning pregnancy
- 23 May 2023
- journal article
- research article
- Published by Oxford University Press (OUP) in Human Reproduction
- Vol. 38 (8), 1601-1612
- https://doi.org/10.1093/humrep/dead100
Abstract
To what extent is male fatty acid intake associated with fecundability among couples planning pregnancy? We observed weak positive associations of male dietary intakes of total and saturated fatty acids with fecundability; no other fatty acid subtypes were appreciably associated with fecundability. Male fatty acid intake has been associated with semen quality in previous studies. However, little is known about the extent to which male fatty acid intake is associated with fecundability among couples attempting spontaneous conception. We conducted an internet-based preconception prospective cohort study of 697 couples who enrolled during 2015–2022. During 12 cycles of observation, 53 couples (7.6%) were lost to follow-up. Participants were residents of the USA or Canada, aged 21–45 years, and not using fertility treatment at enrollment. At baseline, male participants completed a food frequency questionnaire from which we estimated intakes of total fat and fatty acid subtypes. We ascertained time to pregnancy using questionnaires completed every 8 weeks by female participants until conception or up to 12 months. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% CIs for the associations of fat intakes with fecundability, adjusting for male and female partner characteristics. We used the multivariate nutrient density method to account for energy intake, allowing for interpretation of results as fat intake replacing carbohydrate intake. We conducted several sensitivity analyses to assess the potential for confounding, selection bias, and reverse causation. Among 697 couples, we observed 465 pregnancies during 2970 menstrual cycles of follow-up. The cumulative incidence of pregnancy during 12 cycles of follow-up after accounting for censoring was 76%. Intakes of total and saturated fatty acids were weakly, positively associated with fecundability. Fully adjusted FRs for quartiles of total fat intake were 1.32 (95% CI 1.01–1.71), 1.16 (95% CI 0.88–1.51), and 1.43 (95% CI 1.09–1.88) for the second, third, and fourth vs the first quartile, respectively. Fully adjusted FRs for saturated fatty acid intake were 1.21 (95% CI 0.94–1.55), 1.16 (95% CI 0.89–1.51), and 1.23 (95% CI 0.94–1.62) for the second, third, and fourth vs the first quartile, respectively. Intakes of monounsaturated, polyunsaturated, trans-, omega-3, and omega-6 fatty acids were not strongly associated with fecundability. Results were similar after adjustment for the female partner’s intakes of trans- and omega-3 fats. Dietary intakes estimated from the food frequency questionnaire may be subject to non-differential misclassification, which is expected to bias results toward the null in the extreme categories when exposures are modeled as quartiles. There may be residual confounding by unmeasured dietary, lifestyle, or environmental factors. Sample size was limited, especially in subgroup analyses. Our results do not support a strong causal effect of male fatty acid intakes on fecundability among couples attempting to conceive spontaneously. The weak positive associations we observed between male dietary fat intakes and fecundability may reflect a combination of causal associations, measurement error, chance, and residual confounding. The study was funded by the National Institutes of Health, grant numbers R01HD086742 and R01HD105863. In the last 3 years, PRESTO has received in-kind donations from Swiss Precision Diagnostics (home pregnancy tests) and Kindara.com (fertility app). L.A.W. is a consultant for AbbVie, Inc. M.L.E. is an advisor to Sandstone, Ro, Underdog, Dadi, Hannah, Doveras, and VSeat. The other authors have no competing interests to report. N/A.Keywords
Funding Information
- National Institutes of Health
This publication has 74 references indexed in Scilit:
- Impact of obesity on male fertility, sperm function and molecular compositionSpermatogenesis, 2012
- Dietary fat and semen quality among men attending a fertility clinicHuman Reproduction, 2012
- Food intake and social habits in male patients and its relationship to intracytoplasmic sperm injection outcomesFertility and Sterility, 2012
- Trans–fatty acid levels in sperm are associated with sperm concentration among men from an infertility clinicFertility and Sterility, 2011
- A low intake of antioxidant nutrients is associated with poor semen quality in patients attending fertility clinicsFertility and Sterility, 2010
- Soy food and isoflavone intake in relation to semen quality parameters among men from an infertility clinicHuman Reproduction, 2008
- 2006 Marketplace Survey of Trans-Fatty Acid Content of Margarines and Butters, Cookies and Snack Cakes, and Savory SnacksJournal of the American Dietetic Association, 2008
- Effects of Isomeric Fatty Acids on Reproductive Parameters in MiceAmerican Journal of Reproductive Immunology, 2007
- Flexible regression models with cubic splinesStatistics in Medicine, 1989
- Effects of dietarytrans-fatty acids on reproductive performance of Wistar ratsBritish Journal of Nutrition, 1989