- Objective: This study used the Oregon Pregnancy Risk Assessment Monitoring System (PRAMS) to explore the relationship between preconception dietary restriction and subsequent birth outcomes in an attempt to quantify their association. Methods: The survey question of interest focused on changing diet to lose weight during preconception. Descriptive statistics were calculated as proportions for categorical variables and as means with standard deviations for continuous variables. Associations between preconception dieting and birth outcomes were illustrated using contingency tables, odds ratios, and Pearson chi-square statistics for categorical outcomes and independent samples t-tests, t-statistics, and p-values for continuous variables. Results: Of the 6050 women in the study sample, 1365 (26.5%) reported dieting to lose weight before conception. White women ages 24-35 were more likely to diet. 68.8% of dieting women exercised at least 3 days a week; only 38.5% of women exercised but did not diet. The average body mass index of dieting women (28.97 ± 6.80) was 3.18 points higher than non-dieting women, and women who dieted gained more weight during pregnancy. Dieting women were also more likely to have C-sections and babies large for their gestational age (LGA). Conclusion: The higher preconception BMI and weight gain during pregnancy of women who dieted were likely the main factors contributing to the significant associations found between preconception dietary restriction and exercise patterns, C-section rates, and babies who were LGA.
Key Words: preconception, dietary restriction, PRAMS, pregnancy