Fig. 2

Maternal factors and birth size. Adjusted mean ± SEM values of birth weight, length, head circumference SD-scores and ponderal index z-score between (a) maternal prepregnancy BMI groups of underweight, normal weight, overweight and obese; (b) mothers’ inadequate GWG, adequate GWG and excessive GWG; (c) GDM and non-GDM mothers; (d) suboptimal and optimal pregnancy 25(OH)D; and (e) suboptimal and optimal UCB 25(OH)D. Statistical significance is denoted by *P < 0.05, **P < 0.01 and ***P < 0.001. Abbreviations: GWG, gestational weight gain; GDM, gestational diabetes mellitus; 25(OH)D, 25-hydroxy vitamin D; suboptimal, UCB, umbilical cord blood; 25(OH)D < 80 nmol/L; optimal 25(OH)D ≥ 80 nmol/L