Association of maternal 25(OH)D levels during pregnancy with fetal birth weight and preschooler growth status: A retrospective birth cohort study.

Aim: There is limited and conflicting evidence available regarding the correlation between maternal vitamin D status and childhood overweight and body mass index (BMI). The aim of this study was to investigate the following: (1) potential association between maternal 25-hydroxyvitamin D (25(OH)D) levels and newborn growth status; (2) relationship between maternal 25OHD levels and BMI and the risk of overweight with preschoolers being overweight.

Methods: A cohort of 3213 eligible singleton mother-infant pairs were used to investigate the possible associations between maternal 25(OH)D levels and fetal growth status. Data of 1767 available singleton mother-infant pairs and 6-year-old preschoolers was applied to analyze the potential correlations between maternal 25(OH)D status and risk of childhood overweight.

Results: Compared with sufficient 25(OH)D in pregnancy group (≥75 nmol/L), there were no correlations between the maternal 25(OH)D deficiency (<50 nmol/L) and large gestational age (LGA) (p = 0.465), small gestational age (SGA) (p = 0.607), lower birth weight (LBW) (p = 0.725) or fetal macrosomia (p = 0.535). Moreover, no significant associations between insufficient maternal 25(OH)D (50-75 nmol/L) and LGA (p = 0.505), SGA (p = 0.816), LBW (p = 0.816), or fetal macrosomia (p = 0.413) were observed. We found statistically significant disparities between the fetal birth weight and height (p < 0.001), weight (p < 0.001), head circumference (p = 0.001) of 6-years preschooler. No significant associations were found between the maternal 25(OH)D levels and BMI and risk of overweight at 6-year-old preschoolers.

Conclusion: There were no apparent correlation found between maternal 25(OH)D concentrations and fetal birth status. There was no evidence found to suggest the effect of maternal 25(OH)D level on overweight at 6-year-old preschoolers.