Association between maternal vitamin D status with pregnancy outcomes and offspring growth in a population of Wuxi, China.

Background And Objectives: The role of maternal vitamin D in infantile growth remains unclear.

Methods And Study Design: Serum 25-hydroxyvitamin D [25(OH)D] concentrations were examined for pregnancies who visited the Affiliated Wuxi Maternity and Child Health Care Hospital of Nanjing Medical University from January 2016 to December 2017. Anthropometric measurements of corresponding offspring were performed from birth to 2 to 3 years old. Infantile body mass index (BMI) was transformed into age-, sex- and height- normalized z scores, and Latent Class Growth Mixture (LCGM) model was used to identify trajectories of BMI-Z.

Results: Among the 329 included pregnancy women, 109 (33.13 %), 190 (57.75%) and 30 (9.12%) were defined as vitamin D deficiency [25(OH)D <30 nmol/L], insufficiency [30 nmol/L≤25(OH)D<50 nmol/L] and sufficiency [25(OH)D ≥50 nmol/L], respectively. When compared with vitamin D sufficiency, maternal vitamin D deficiency was not associated with preterm birth [odds ratio (OR)=2.69, 95% confidence interval (95% CI)=0.57-12.80], small for gestation age (OR=0.99, 95% CI=0.29-3.46), and low birth weight (OR=1.69, 95% CI=0.34-8.51). Similarly, no significant relationships were found between maternal vitamin D concentrations and anthropometric indices (such as weight, length, BMI) during 0 to 3 years old. Furthermore, LCGM model identified two patterns of offspring growth: stable moderate BMI-Z and early transient BMI-Z groups. Maternal vitamin D levels were higher in the former group than the latter (p=0.037); however, maternal vitamin D status appeared to be unrelated with offspring BMI-Z trajectories in multivariable logistic regression models.

Conclusions: Maternal vitamin D deficiency may not be related to adverse pregnancy outcomes as well as offspring growth.