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What is the relationship between dietary patterns consumed during pregnancy and gestational age at birth?

Approach to Answering the Question
Existing NESR Systematic Review

Pregnancy and Lactation Subcommittee

Existing Systematic Review Protocol
Developed for each scientific question being examined, the protocol describes the plan for how the systematic review will be conducted. For this question, the existing NESR systematic review was conducted during the Pregnancy and Birth to 24 Months Project, and captured evidence published from January 1980 to January 2017. The Pregnancy Technical Expert Collaborative conducted the systematic reviews in collaboration with staff from USDA’s Nutrition Evidence Systematic Review (NESR). Complete documentation of the existing systematic review and the related publication in the American Journal of Clinical Nutrition is available on the NESR website:

For additional details, see the full protocol for the question, What is the relationship between dietary patterns consumed during pregnancy and gestational age at birth?

View Full Protocol

Draft Conclusion Statement

The draft conclusion statements listed below describe the state of the science related to the specific question examined. Draft conclusions are not considered final until they have been deliberated with and decided upon by the full Committee and published in the Committee’s final advisory report. Individual conclusion statements should not be interpreted as dietary guidance or the Committee’s overarching advice to the Departments. 

Limited but consistent evidence suggests that certain dietary patterns during pregnancy are associated with a lower risk of preterm birth and spontaneous preterm birth. These protective dietary patterns are higher in vegetables, fruits, whole grains, nuts, legumes and seeds, and seafood (preterm birth 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. Grade: Limited

Evidence is insufficient to estimate the association between dietary patterns before pregnancy and gestational age at birth as well as the risk of preterm birth. Grade: Grade Not Assignable