An Empirical Dietary Inflammatory Pattern and Fecundability in a Multiethnic Asian Preconception Cohort.

BACKGROUND

Inflammation is known to adversely affect fertility but few studies have related dietary inflammatory potential to conception in women without known infertility.

OBJECTIVES

This study aimed to empirically derive a dietary inflammatory pattern score for Singaporean women (EDIP-SGW) and examined its association with fecundability in women from the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO) study.

METHODS

The EDIP-SGW score was calculated based on a dietary pattern (derived from food frequency questionnaire data using reduced rank regression) most predictive of 2 inflammatory markers: high-sensitivity C-reactive protein and glycoprotein acetyls. We validated the score in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) study. Fecundability (measured by time-to-pregnancy in menstrual cycles within a year of enrolment) for increasing EDIP-SGW score was estimated using discrete-time proportional hazards models adjusted for covariates (n = 890). Interaction with insulin resistance [homeostatic model assessment for insulin resistance (HOMA-IR)] was explored.

RESULTS

Increasing concentrations of high-sensitivity C-reactive protein and glycoprotein acetyls were observed across EDIP-SGW score quartiles in both the S-PRESTO and GUSTO, demonstrating the score's validity. Fecundability was 34% lower in the highest quartile of EDIP-SGW scores compared with the lowest quartile (fecundability ratio: 0.66, 95% confidence interval: 0.48, 0.93), and each SD increase in EDIP-SGW score was associated with a 13% lower fecundability [0.87 (0.77, 0.99)]. Among women with low HOMA-IR (<2.5), those in the highest quartile of EDIP-SGW scores appeared to have a 34% lower fecundability [0.66 (0.46, 0.94); P-interaction = 0.004], but this was not evident in women with high HOMA-IR (≥2.5).

CONCLUSIONS

A proinflammatory diet is associated with lower fecundability in multiethnic Asian women without known infertility. Further studies are needed to clarify the role of insulin resistance in this relationship.