Intake of protein-rich foods in relation to outcomes of infertility treatment with assisted reproductive technologies

Abstract

Background: Some dietary factors have been linked to outcomes of infertility treatment with assisted reproductive technology (ART), but the role of intake of meats and other protein-rich foods remains unclear.

Objective: The aim of this manuscript was to study the relation between preconception intake of meat and other protein-rich foods and outcomes of infertility treatment with ART.

Design: A total of 351 women enrolled in a prospective cohort at the Massachusetts General Hospital Fertility Center and underwent 598 ART cycles for infertility treatment. Meat intake was assessed with a validated food-frequency questionnaire, and ART outcomes were abstracted from electronic medical records. We estimated the associations between intake of protein-rich foods (meats, eggs, beans, nuts, and soy) and the outcome of live birth per initiated cycle using generalized linear mixed models.

Results: The average total meat intake was 1.2 servings/d, with most coming from poultry (35%), fish (25%), processed meat (22%), and red meat (17%). Fish intake was positively related to the proportion of cycles resulting in live birth. The multivariable-adjusted probabilities of live birth for women in increasing quartiles of fish intake were 34.2% (95% CI: 26.5%, 42.9%), 38.4% (95% CI: 30.3%, 47.3%), 44.7% (95% CI: 36.3%, 53.4%), and 47.7% (95% CI: 38.3%, 57.3%), respectively (P-trend = 0.04). In the estimated substitution analyses, the ORs of live birth associated with increasing fish intake by 2 servings/wk were 1.54 (95% CI: 1.14, 2.07) when fish replaced any other meat, 1.50 (95% CI: 1.13, 1.98) when fish replaced any other protein-rich food, and 1.64 (95% CI: 1.14, 2.35) when fish replaced processed meat.

Conclusions: Fish consumption is related to a higher probability of live birth following infertility treatment with ART. This trial was registered at clinicaltrials.gov as NCT00011713.

Figures

FIGURE 1

Total meat, eggs, and vegetable sources of protein-rich foods (beans, nuts, and soy) and clinical outcomes analysis in the EARTH Study (n = 351 women; 598 cycles). Data are presented as predicted marginal means with 95% CIs adjusted for total daily calories, age, BMI, race, smoking status, daily supplemental dietary folate, supplemental vitamin B-12, supplemental iron intake, supplemental ω-3 (binary, yes/no), and prudent and Western dietary patterns (excluding meats), with all continuous variables at their mean level and all categorical variables at their weighted average level. All analyses were adjusted for all the other protein-rich foods. All outcomes were analyzed using generalized linear mixed models with random intercepts, binary distribution, and logit link function. Test for trend was performed using a continuous variable for the median number of servings per day for each quartile of the corresponding meat intake in the regression models. EARTH Study, Environment and Reproductive Health Study.

FIGURE 2

Fish and red meat intake and clinical outcomes analysis in the EARTH Study (n = 351 women; 598 cycles). Data are presented as predicted marginal means with 95% CIs adjusted for total daily calories, age, BMI, race, smoking status, daily supplemental dietary folate, supplemental vitamin B-12, supplemental iron intake, supplemental ω-3 (binary, yes/no), and prudent and Western dietary patterns (excluding meats). All analyses were adjusted for all the other protein-rich foods. All outcomes were analyzed using generalized linear mixed models with random intercepts, binary distribution and logit link function. Test for trend was performed using a continuous variable for the median number of servings per day for each quartile of the corresponding meat intake in the regression models. *P < 0.05 when compared with the lowest category of intake. EARTH Study, Environment and Reproductive Health Study.

FIGURE 3

ORs (95% CIs) of live birth per treatment cycle initiated associated with substituting 1) fish or 2) red meat for other food sources (2 servings/wk) in the EARTH Study (n = 351 women; 598 cycles). (A) Fish estimated substitutions (2 servings/wk). (B) Red meat estimated substitutions (2 servings/wk). All outcomes were analyzed using generalized linear mixed models with random intercepts, binary distribution, and logit link function. All analyses were adjusted for total daily calories, age, BMI, race, smoking status, daily supplemental dietary folate, supplemental vitamin B-12, supplemental iron intake, supplemental ω-3 (binary, yes/no), and prudent and Western dietary patterns (excluding meats). All analyses were adjusted for all the other protein-rich foods (i.e., processed meat, red meat, organ meat, fish, poultry and vegetarian; servings per day). All outcomes were analyzed using generalized linear mixed models with random intercepts, binary distribution, and logit link function. “Any other protein-rich food” includes all other meats, eggs, and beans, soy, and nuts. EARTH Study, Environment and Reproductive Health Study.