Nutrition/Obesity
Examining the role of early pregnancy dietary intake on preterm birth using target trial emulations Kyle Busse* Kyle Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse Busse University of Pennsylvania
Introduction: Adhering to a healthy diet may reduce the risk of preterm birth, but it remains unclear which dietary strategies are most effective, as trials of dietary interventions in pregnancy are often infeasible. We estimated the observational analogs of the intention-to-treat effects of hypothetical interventions to meet 2015-2020 Dietary Guidelines for Americans (DGA) recommendations in pregnancy on the risk of preterm birth.
Methods: We used data from 10,095 pregnancies (10,069 people) in the Environmental influences on Child Health Outcomes (ECHO) Cohort with diet assessed before 20 weeks’ gestation. Discrete interventions were defined as: 1) achieving a Healthy Eating Index-2015 (HEI) score ≥60th percentile; 2) meeting recommendations for ≥7 of 13 DGA components; 3) meeting recommendations for total fruits and vegetables; 4) meeting recommendations for all “moderation” components (sodium, refined grains, saturated fats, added sugars); 5) meeting recommendations for ≥2 moderation components. Modified Poisson regression with robust standard errors estimated risk ratios (RR) and 95% confidence intervals (CI) for preterm birth (<37 weeks’), adjusted for age, race, ethnicity, education, parity, pre-pregnancy BMI, household income, alcohol and tobacco use, and plurality. Multiple imputation (m=20) was used for missing covariate data.
Results: 1,044 deliveries (10%) were preterm. Achieving a HEI score ≥60th percentile (score of 67, RR=0.84 [95% CI 0.74-0.94]), meeting recommendations for ≥7 DGA components (17% of pregnancies, RR=0.86 [0.73-1.01]), and meeting recommendations for total fruits and vegetables (24%, RR=0.86 [0.75-0.98]) were associated with a lower risk of preterm birth. Meeting recommendations for all (1%) or ≥2 moderation components (20%) was not associated with preterm birth.
Conclusions: Identifying strategies to help pregnant people meet recommendations for overall diet quality and fruit and vegetable intake may reduce the risk of preterm birth.