Associations between maternal dietary patterns and infant birth weight, small and large for gestational age in the Norwegian Mother and Child Cohort Study

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. 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. Compared to the high Western group, the high prudent group was associated with lower birth weight ( β ultrasound z -scores −0.041 (95% confidence interval (CI): −0.068, −0.013)) and the high traditional group with higher birth weight ( β ultrasound 0.067 (95% CI: 0.040, 0.094)) for all three growth standards. The high prudent pattern was associated with increased SGA risk (SGA ultrasound odds ratio (OR) 1.25 (95% CI: 1.02, 1.54)) and decreased LGA risk (LGA population OR 0.84 (95% CI: 0.75, 0.94)), while the high traditional group on the contrary was associated with decreased SGA (SGA customized OR 0.92 (95% CI: 0.84, 0.99)) and increased LGA risk (LGA population OR 1.12 (95% CI: 1.02, 1.24)). 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.