Dietary Fat Intake and Fecundability in 2 Preconception Cohort Studies

Am J Epidemiol. 2018 Jan 1;187(1):60-74. doi: 10.1093/aje/kwx204.


The association between dietary fat and fertility is not well studied. We evaluated intakes of total fat, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, trans fatty acids (TFA), ω-3 fatty acids, and ω-6 fatty acids in relation to fecundability in Danish and North American preconception cohort studies. Women who were attempting to become pregnant completed a validated food frequency questionnaire at baseline. Pregnancy status was updated bimonthly for 12 months or until pregnancy. Fecundability ratios (FR) and 95% confidence intervals were estimated using multivariable proportional probabilities regression. Intakes of total fat and saturated, monounsaturated, polyunsaturated, and ω-6 fatty acids were not appreciably associated with fecundability. TFA intake was associated with reduced fecundability in North American women (for the fourth quartile vs. the first, FR = 0.86, 95% confidence interval (CI): 0.71, 1.04) but not Danish women (for the fourth quartile vs. the first, FR = 1.04, 95% CI: 0.86, 1.25), though intake among Danish women was low. In North America, ω-3 fatty acid intake was associated with higher fecundability, but there was no dose-response relationship (among persons who did not use fish oil supplements: for the fourth quartile vs. the first, FR = 1.40, 95% CI: 1.13, 1.73); no association was found in Danish women, among whom low intake was rare. In the present study, high TFA intake and low ω-3 fatty acid intake were associated with reduced fecundity.

Keywords: fatty acids; fertility; internet; prospective studies; trans fatty acids.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cohort Studies
  • Denmark
  • Diet Surveys
  • Dietary Fats / adverse effects
  • Dietary Fats / analysis*
  • Eating
  • Fatty Acids, Omega-3 / adverse effects
  • Fatty Acids, Omega-3 / analysis
  • Fatty Acids, Omega-6 / adverse effects
  • Fatty Acids, Omega-6 / analysis
  • Female
  • Fertility*
  • Humans
  • Infertility, Female / epidemiology
  • Infertility, Female / etiology*
  • Middle Aged
  • Multivariate Analysis
  • North America
  • Nutritional Status
  • Preconception Care / statistics & numerical data
  • Pregnancy
  • Pregnancy Rate
  • Proportional Hazards Models
  • Trans Fatty Acids / adverse effects
  • Trans Fatty Acids / analysis*
  • Young Adult


  • Dietary Fats
  • Fatty Acids, Omega-3
  • Fatty Acids, Omega-6
  • Trans Fatty Acids