Relation of 25-hydroxy vitamin D and onset of labor

Aims: The active form of vitamin D affects mineral homeostasis and bone metabolism. Stimulation effect of vitamin D in early pregnancy is effective for fetal-placental growth and development. The aim of this study is to investigate the relationship between 25-hydroxy vitamin D and initiation of labor. Materials & Methods: This study was conducted in Taleghani Hospital in Arak in 2008. 152 normal pregnant women were divided into two groups of having symptoms of labor initiation (76 cases) and without symptoms of labor initiation (76 cases). 25-hydroxy vitamin D, parathyroid hormone, calcium, phosphorus, phosphatase alkaline and magnesium of the blood were analyzed by Mann-Whitney U, linear logistic regression and student T test. Results: The mean level of 25-Hydroxy vitamin D in plasma of the labor group were more than the non-labor group (59.78±2.08 vs. 51.66±2.04 nmol/l p=0.006). The mean difference of parathyroid hormone was not significant between two groups. The mean differences of calcium, phosphorus, phosphatase alkaline and magnesium was not significant in the two groups, too. Conclusion: Considering the mean difference of 25-hydroxy vitamin D in two groups and lack of difference in the mean of parathyroid hormone, calcium, magnesium, phosphorus and phosphatase alkaline in both groups, there is the possibility of the existence 25-hydroxy vitamin D’s effect at the initiation of the labor.