The Effect of Cord Blood Vitamin D Level on Bronchopulmonary Dysplasia and Other Neonatal Morbidities in Preterm Infants

Abstract

OBJECTIVES: We aimed to investigate the relationship between cord 25-hydroxyvitamin D level and bronchopulmonary dysplasia and other neonatal morbidities (sepsis, necrotizing enterocolitis, intraventricular hemorrhage, patent ductus arteriosus, respiratory distress syndrome, retinopathy of prematurity) in preterm neonates.

STUDY DESIGN: Infants aged <32 gestational weeks who were admitted to the neonatal intensive care unit between March 2014 and November 2014 were enrolled in this prospective study. Cord blood samples were obtained during delivery. 25-hydroxyvitamin D level was measured using an automatic biochemical analyzer. Patients were divided into two groups according to their 25-hydroxyvitamin D levels: 25-hydroxyvitamin D <20 ng/mL and 25-hydroxyvitamin D ≥20 ng/mL. We used descriptive statistics and multiple regression models to identify risk factors associated with bronchopulmonary dysplasia.

RESULTS: Sixty premature infants were analyzed in this study. The mean cord 25-hydroxyvitamin D level was 13,8±6,8 ng/mL (range 3,5-30,7 ng/mL). Eighty percent of the patients (48/60) had 25-hydroxyvitamin D levels <20 ng/mL. Among the infants, 21 (35%) developed bronchopulmonary dysplasia. Infants with bronchopulmonary dysplasia had higher frequencies of 25-hydroxyvitamin D deficiency than the non-bronchopulmonary dysplasia group (p=0.028). Duration of hospitalization was also longer in infants with low levels of cord 25-hydroxyvitamin D. On the other hand, there was no significant difference between infants with and without vitamin D deficiency with respect to respiratory distress syndrome, patent ductus arteriosus, retinopathy of prematurity, necrotizing enterocolitis, sepsis, and intraventricular hemorrhage.

CONCLUSION: This study shows the high rate of vitamin D deficiency in pregnant women in the central Anatolian region (Sivas) of Turkey. Low cord 25-hydroxyvitamin D levels were associated with an increased risk of bronchopulmonary dysplasia and prolonged hospitalization in very preterm infants. These data strengthen the necessity for vitamin D supplementation during pregnancy.