Evaluation of Maternal Serum 25-Hydroxyvitamin D, Paraoxonase 1 Levels, and Neutrophil-to-Lymphocyte Ratio in Spontaneous Preterm Birth

Background: The aim of this study was to evaluate the association of maternal serum 25-hydroxyvitamin D, paraoxonase 1, and neutrophil-to-lymphocyte ratio in women having early spontaneous preterm birth without clinical chorioamnionitis. Material/Methods: This study was prospectively administered in women referred to our obstetrics service with preterm labor that resulted in preterm birth (n=35) and term labor that ended in term birth (n=44). The maternal serum levels of 25-hydroxyvitamin D and paraoxonase 1 were measured and neutrophil-to-lymphocyte ratio was calculated. Results: The 25-hydroxyvitamin D and paraoxonase 1 levels of the preterm group were significantly lower than those of the term group (p<0.05). The neutrophil-to-lymphocyte ratio value of the preterm group was significantly higher than that of the term group (p<0.05). There was a significant but small positive correlation between the serum levels of 25-hydroxyvitamin D and paraoxonase 1 in the preterm group (r=0.35; p=0.021). Conclusions: Decreased maternal serum 25-hydroxyvitamin D and paraoxonase 1 levels and increased neutrophil-to-lymphocyte ratio may have a role in the etiology of spontaneous preterm birth.