Poster Topical Area: Maternal, Perinatal and Pediatric Nutrition
Location: Hall D
Poster Board Number: 291
Objectives: Preterm birth (PTB) is an important cause of perinatal morbidity and mortality in the United States. A systematic review was conducted as part of the USDA-HHS Pregnancy and Birth to 24 Months Project to assess the relationship between dietary patterns (DP) before and during pregnancy and gestational age at birth.
Methods: Nine databases, including PubMed, Embase, Cochrane, and CINAHL, were searched from January 1980 to January 2017 for peer-reviewed articles related to DP and pregnancy/birth outcomes. Articles were dual-screened using a priori inclusion/exclusion criteria; then, relevant information was extracted from included articles and the risk of bias was assessed. After qualitatively synthesizing the data, a conclusion statement was drafted to answer the systematic review question and the evidence was graded. Finally, recommendations for future research were identified.
Results: Of the 9,103 search results, 11 studies representing 7 cohorts and 1 randomized controlled trial met the criteria for inclusion. Sample sizes ranged from 290 to 72,072 subjects. Five of the 8 studies that examined DP during pregnancy and PTB found a significant association. A sixth study found a significant association with early PTB (<35 wks) but not PTB (<37 wks). Additionally, 4 of the 5 studies that examined DP during pregnancy and spontaneous PTB found a significant association. Only 3 studies assessed DP before and/or during pregnancy and gestational age at birth as a continuous outcome. Overall, the DASH diet, the Mediterranean diet, the New Nordic Diet, and others DP were protective. The body of evidence was limited in several ways (e.g., the methods used across studies varied considerably, and minority and lower SES populations were underrepresented).
Conclusions: Limited but consistent evidence suggests that DP during pregnancy are associated with a lower risk of PTB and spontaneous PTB. These protective DP are higher in vegetables; fruits; whole grains; nuts, legumes, and seeds; and seafood (PTB, only) and lower in red and processed meats and fried foods. Most of the research was conducted in healthy, Caucasian women with access to health care. Evidence is insufficient to estimate the association between DP before pregnancy and gestational age at birth as well as the risk of PTB. Additional research is needed.
Center for Nutrition Policy and Promotion, Food and Nutrition Service, USDA, Alexandria, VA and the Office of Disease Prevention and Health Promotion, Office of the Assistant Secretary for Health, US Department of Health and Human Services, Rockville, MD.