Maternal Vitamin D Deficiency and the Risk of Small for Gestational Age: A Meta-analysis

Area of Science:

• Obstetrics and Gynecology
• Nutritional Science
• Perinatal Medicine

Background:

• Existing research presents conflicting findings on the relationship between maternal vitamin D deficiency and the risk of small for gestational age (SGA).
• Clarifying this association is crucial for understanding potential interventions during pregnancy.

Purpose of the Study:

• To conduct a meta-analysis of observational studies to evaluate the association between maternal vitamin D deficiency and the risk of SGA.

Main Methods:

• A comprehensive literature search was performed across major electronic databases (PubMed, Medline, Web of Science, Embase, Cochrane Library) up to December 2016.
• Keywords included various forms of vitamin D and terms related to fetal growth and pregnancy outcomes.
• Twelve observational studies involving 19,027 participants were included in the meta-analysis.

Main Results:

• Maternal vitamin D deficiency (defined as 25-hydroxyvitamin D [25-OHD] levels <50 nmol/L) was associated with a significantly increased risk of SGA (Odds Ratio = 1.41, 95% CI: 1.14, 1.75).
• Infants born small for gestational age had lower maternal vitamin D concentrations compared to non-SGA infants (Mean Difference = -1.75 nmol/L, 95% CI: -3.23, -0.27).

Conclusions:

• Maternal vitamin D deficiency during pregnancy is a potential risk factor for delivering a small for gestational age infant.
• These findings underscore the importance of monitoring and potentially supplementing vitamin D levels in pregnant women to improve fetal growth outcomes.