Dietary patterns before and during pregnancy and birth outcomes: a systematic review

Abstract

Background Maternal diet before and during pregnancy could influence fetal growth and birth outcomes. Objective Two systematic reviews aimed to assess the relationships between dietary patterns before and during pregnancy and 1) gestational age at birth and 2) gestational age- and sex-specific birth weight. Methods Literature was searched from January, 1980 to January, 2017 in 9 databases including PubMed, Embase, and Cochrane. Two analysts independently screened articles using predetermined inclusion and exclusion criteria. Data were extracted from included articles and risk of bias was assessed. Data were synthesized qualitatively, a conclusion statement was drafted for each question, and evidence supporting each conclusion was graded. Results Of the 9103 studies identified, 11 [representing 7 cohorts and 1 randomized controlled trial (RCT)] were included for gestational age and 21 (representing 19 cohorts and 2 RCTs) were included for birth weight. 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. No conclusion can be drawn on the association between dietary patterns during pregnancy and birth weight outcomes. Although research is available, the ability to draw a conclusion is restricted by inconsistency in study findings, inadequate adjustment of birth weight for gestational age and sex, and variation in study design, dietary assessment methodology, and adjustment for key confounding factors. Insufficient evidence exists regarding dietary patterns before pregnancy for both outcomes. Conclusions Maternal dietary patterns may be associated with a lower preterm and spontaneous preterm birth risk. The association is unclear for birth weight outcomes.

Prevention of noncommunicable diseases by interventions in the preconception period: A FIGO position paper for action by healthcare practitioners

“…A healthy diet before conception may reduce pregnancy complications such as GDM and hypertension 54,55 . The nutritional guidelines for women contemplating pregnancy show great diversity between countries and we recommend that local dietary practices based on personal or religious beliefs are taken into consideration when providing nutrition advice.…”

Management of prepregnancy, pregnancy, and postpartum obesity from the FIGO Pregnancy and Non‐Communicable Diseases Committee: A FIGO (International Federation of Gynecology and Obstetrics) guideline

“…Dietary advice should therefore emphasize healthy dietary patterns that consist of nutrient‐dense foods. This may be characterized by higher intakes of fruit, vegetables, wholegrains, nuts, seeds, legumes, and seafood, and lower intakes of red or processed meats and fried foods 82–84 . The specific foods advised however will vary depending on the context and must be culturally and locally relevant 82–84 .…”

Socioeconomic Disparities of Low Birth Weight in Rural Indonesia

“…Meanwhile, the limitation is that because this is a cross-sectional study, the authors cannot confirm a temporal relationship between exposure and outcome variables. Another limitation is that it did not investigate some of the known risk factors from previous studies for LBW, including dietary and nutritional factors 42,43 , genetic factors, and [44][45][46] , as well as pollution and environmental factors 47,48 . This limitation is more due to limited secondary data from the 2017 IDHS.…”