Background/objectives: To assess whether quality of maternal diet affects birth weight and the risk of small for gestational age (SGA) and/or large for gestational age (LGA) babies.
Subjects/methods: This study is based on the Norwegian Mother and Child Cohort Study (MoBa) and includes 65,904 pregnant women who answered a validated food frequency questionnaire at mid-pregnancy. Three maternal dietary patterns were extracted based on characteristics of food items in each pattern. From these we created four non-overlapping groups: "high prudent," "high Western," "high traditional," and "mixed". We obtained information about birth weight from the Norwegian Medical Birth Registry and calculated birth weight z-scores, SGA, and LGA according to an ultrasound-based, population-based, and a customized growth standards. Associations were studied by linear and multiple logistic regression.
Results: Compared to the high Western group, the high prudent group was associated with lower birth weight (βultrasound z-scores -0.041 (95% confidence interval (CI): -0.068, -0.013)) and the high traditional group with higher birth weight (βultrasound 0.067 (95% CI: 0.040, 0.094)) for all three growth standards. The high prudent pattern was associated with increased SGA risk (SGAultrasound odds ratio (OR) 1.25 (95% CI: 1.02, 1.54)) and decreased LGA risk (LGApopulation OR 0.84 (95% CI: 0.75, 0.94)), while the high traditional group on the contrary was associated with decreased SGA (SGAcustomized OR 0.92 (95% CI: 0.84, 0.99)) and increased LGA risk (LGApopulation OR 1.12 (95% CI: 1.02, 1.24)).
Conclusions: Food quality was associated with birth weight in this well-nourished Norwegian population. Food quality may affect a woman's risk of giving birth to a SGA or LGA baby.