Maternal vitamin B₃ and C intake in pregnancy influence birth weight at term

The objective of this study was to examine the influence of maternal nutrient intake during pregnancy on the baby's birth weight at term.

A cross-sectional study design was used to evaluate a sample of women aged 18 to 44 y in the postpartum period in a public maternity department (2018-2019), with dietary intake collected by a validated food frequency questionnaire (n = 626 mother-offspring pairs). A multivariable linear regression model was used to identify the influence of nutrient intake during pregnancy on the baby's birth weight at term. The model was adjusted for maternal energy intake, education level, gestational age, physical activity, and supplementation during pregnancy.

Maternal intake of vitamins B₃ and C was associated with an increase in birth weight (respectively, β = 0.01; 95% confidence interval [CI], 0.01-0.02; P = 0.01; and β = 0.01; 95% CI, 0.01-0.02; P = 0.02). Prepregnancy body mass index (β = 0.01; 95% CI, 0.01-0.02; P = 0.001), gestational weight gain (β = 0.02; 95% CI, 0.01-0.02; P < 0.001), parity (β = 0.05; 95% CI, 0.02-0.09; P = 0.001), and male babies (β = 0.08; 95% CI, 0.01-0.02; P = 0.02) also contributed to increase birth weight. These variables explained about 27% of the variation of this outcome (adjusted R² = 0.27, P < 0.001).

Our findings provide evidence that maternal intake of vitamins B₃ and C influences increased birth weight. In addition, prepregnancy body mass index, gestational weight gain, parity, and male babies contribute to the same outcome.