Maternal serum vitamin D levels and preterm delivery among low-risk parturients in Lagos, Nigeria.

Objective: To determine the association between low maternal vitamin D levels and preterm delivery among parturients in Lagos, Nigeria.

Methods: The present study was an analytical cross-sectional study of women with preterm deliveries (defined as <37 weeks) and women with term deliveries (defined as ≥37 weeks) at the labor unit of Lagos University Teaching Hospital between December 1, 2015, and October 31, 2016. Relevant information was obtained via a proforma, and maternal venous samples were collected immediately after delivery. Serum 25-hydroxy vitamin D was determined by a vitamin D enzyme-linked immunoassay kit.

Results: The study enrolled 103 women in each group. The overall prevalence of vitamin D deficiency was 14.1% (29/206). 24 (23.3%) women with preterm delivery had low serum vitamin D (<30 ng/mL) as compared with only 5 (4.9%) women with term delivery (P<0.001). Compared with normal serum vitamin D levels, low maternal vitamin D had an approximately nine-fold higher likelihood of preterm delivery (adjusted odds ratio 9.41, 95% confidence interval 2.42-36.54; P<0.001).

Conclusion: The prevalence of serum vitamin D deficiency was higher among women with preterm delivery than among those with term delivery. The potential role of prenatal vitamin D supplementation in the prevention of preterm delivery should be further investigated.