Prepregnancy adherence to plant-based diet indices and exploratory dietary patterns in relation to fecundability

Abstract

Background Modest associations have been reported between specific food groups or nutrients and fecundability [measured by time to pregnancy (TTP)]. Examining overall diets provides a more holistic approach towards understanding the relationships with fecundability. It is not known if plant-based diets indices or exploratory dietary patterns are associated with fecundability. Objective We examine the associations between adherence to 1) plant-based diet indices and 2) exploratory dietary patterns and fecundability among women planning pregnancy. Design Data were analysed from the Singapore S-PRESTO study. Pre-pregnancy diet was assessed using a semi-quantitative food frequency questionnaire from which the overall, healthful and unhealthful plant-based diet indices (oPDI, hPDI and uPDI) were calculated. Exploratory dietary patterns were derived using factor analysis based on forty-four pre-defined food groups. Participants were categorized into quintiles based on their dietary pattern scores. TTP (in menstrual cycles) was ascertained within a year of dietary assessment. Discrete-time proportional hazard models, adjusted for confounders, were used to estimate fecundability ratios (FRs) and 95% CIs, with FR > 1 indicating a shorter TTP. Results Among 805 women, 383 pregnancies confirmed by ultrasound scans occurred. Compared to women in the lowest quintile, those in the highest quintile of the uPDI had reduced fecundability [FR of Q5 vs Q1 (95% CI): 0.65 (0.46, 0.91), p trend: 0.009]. Conversely, greater adherence to the hPDI was associated with increased fecundability [1.46 (1.02, 2.07), p trend: 0.036]. The oPDI was not associated with fecundability. Among the three exploratory dietary patterns, only greater adherence to the “Fast Food and Sweetened Beverages” pattern (FFSB) was associated with reduced fecundability [0.61 (0.40, 0.91), p trend: 0.018]. Conclusions Greater adherence to the uPDI or the FFSB dietary pattern was associated with reduced fecundability among Asian women. Greater adherence to the hPDI may be beneficial for fecundability, though this requires confirmation by future studies. Clinical Trial Registry number: NCT 03531658 Secondary Abstract: Plant-based diets are increasingly popular as they are associated with reduced risks of chronic diseases and considered a sustainable diet for planetary health. Do these diets contribute to fecundability (as measured by time to pregnancy)?

Modifiable Risk Factor Score and Fecundability in a Preconception Cohort in Singapore

“…These values were converted to obtain daily intake in serving size. To facilitate the application of the risk score in populations, we used the vegetable component as a surrogate marker for a healthful diet, based on evidence showing that a healthy plant-based diet was associated with increased fecundability . Vegetable intake comprising a sum of leafy vegetables, cruciferous vegetables, and peas was classified into less than 2 servings per day to represent an unhealthy diet or 2 or more servings per day to represent a healthy diet…”

“…In secondary analyses, instead of vegetable intake of less than 2 servings per day, we used a different definition of unhealthy diet as a risk factor: the median level of healthful plant-based diet index (PDI) with a score of 47 or lower in pregnant participants . We also repeated the main analysis using a weighted risk score.…”

“…To facilitate the application of the risk score in populations, we used the vegetable component as a surrogate marker for a healthful diet, based on evidence showing that a healthy plant-based diet was associated with increased fecundability. 12 Vegetable intake comprising a sum of leafy vegetables, cruciferous vegetables, and peas was classified into less than 2 servings per day to represent an unhealthy diet or 2 or more servings per day to represent a healthy diet. 13 Participants were asked whether they had ever smoked regularly (at least once a day for a year or more) and were currently smoking, and their status was then classified as ever (current or past) smokers or never smokers.…”

Dietary Supplement Intake and Fecundability in a Singapore Preconception Cohort Study

“…Alcohol intake was assessed as any alcohol intake in the last three months. Derivation of uPDI and total daily energy intake were based on a validated food frequency questionnaire, as described previously [ 42 ]. uPDI was grouped into tertiles, with a higher score denoting consumption of more unhealthful plant-based food components.…”

Pre-pregnancy check-up of maternal vascular status and associated phenotype is crucial for the health of mother and offspring

“…Individualised dietary patterns composed before, during and after pregnancy may be health protective for both the mother and offspring [53,54]. Based on the available evidence, herewith we exemplify protective effects of natural substances adapted to individual risks listed below.…”