Protein intake and ovulatory infertility

Am J Obstet Gynecol. 2008 Feb;198(2):210.e1-7. doi: 10.1016/j.ajog.2007.06.057.


Objective: The objective of the study was to evaluate whether intake of protein from animal and vegetable origin is associated with ovulatory infertility.

Study design: A total of 18,555 married women without a history of infertility were followed up as they attempted a pregnancy or became pregnant during an 8 year period. Dietary assessments were related to the incidence of ovulatory infertility.

Results: During follow-up, 438 women reported ovulatory infertility. The multivariate-adjusted relative risk (RR) (95% confidence interval [CI]; P for trend) of ovulatory infertility comparing the highest to the lowest quintile of animal protein intake was 1.39 (1.01 to 1.90; 0.03). The corresponding RR (95% CI; P for trend) for vegetable protein intake was 0.78 (0.54 to 1.12; 0.07). Furthermore, consuming 5% of total energy intake as vegetable protein rather than as animal protein was associated with a more than 50% lower risk of ovulatory infertility (P =.007).

Conclusion: Replacing animal sources of protein with vegetable sources of protein may reduce ovulatory infertility risk.

Publication types

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

MeSH terms

  • Adult
  • Diet Surveys
  • Dietary Proteins / administration & dosage*
  • Dietary Proteins / pharmacology
  • Female
  • Humans
  • Infertility, Female / epidemiology*
  • Infertility, Female / etiology
  • Infertility, Female / prevention & control*
  • Meat*
  • Ovulation / drug effects*
  • Plant Proteins, Dietary / administration & dosage*
  • Plant Proteins, Dietary / pharmacology
  • Pregnancy
  • Prospective Studies
  • Risk Factors
  • Surveys and Questionnaires
  • United States


  • Dietary Proteins
  • Plant Proteins, Dietary