Risk Factors for Nephrocalcinosis in Very Low Birth Weight Infants

Abstract

Objective: The objective was to identify risk factors for nephrocalcinosis in very low birth weight (VLBW) infants. Methods: Prospective study has done between 2014 and 2017. The study included 81 VLBW infants in the neonatal intensive care unit (NICU). Renal ultrasonography was performed at four weeks and 3 months. Baseline characteristics, complications and medication during NICU admission were collected. 25-(OH)-vitamin D, calcium, phosphorous, alkaline phosphatase, urine calcium to creatinine ratio were serially measured. Results: The incidence of nephrocalcinosis was 16.9%. On univariate analysis, gestational age, lower birth weight, maternal pregnancy-induced hypertension, neonatal sepsis, and frequency of vancomycin and caffeine citrate treatment were significantly associated with nephrocalcinosis. In addition, preterm infants with nephrocalcinosis had lower cord blood 25-(OH)-vitamin D and serum calcium levels and higher serum alkaline phosphatase levels at 2 weeks of life. Multivariate analysis showed that gestational age (P=0.042), birth weight (P=0.019), sepsis (P=0.046), small for gestational age (P=0.015), and maternal pregnancy-induced hypertension (P=0.024) were significant risk factors for nephrocalcinosis. Conclusion: This study suggests that neonatal sepsis and maternal pregnancy-induced hypertension, in addition to gestational age and birth weight are important perinatal risk factors for nephrocalcinosis.