Incidence and risk factors of subclinical umbilical catheter-related thrombosis in neonates.

INTRODUCTION: This study aimed to determine the risk factors for subclinical umbilical catheter-related thrombosis (UCRT) and its association with clinical morbidities.

MATERIALS AND METHODS: In infants without any symptoms associated with umbilical catheterization, the presence of thrombosis was monitored using abdominal ultrasonography within 1 week after umbilical catheter removal. The association between UCRT and the clinical variables was analyzed by comparing the groups with and without UCRT.

RESULTS: UCRT occurred in 26 (19.0%) of 137 infants. The relative incidence rate of thrombosis was 12.3% at the umbilical artery and 21.7% at the umbilical vein. However, the type of umbilical vessels with a catheter was not associated with thrombosis (P = 0.095). Subclinical UCRT was associated with high serum calcium concentration in the multivariate analysis (95% confidence interval, 1.26-15.32; P = 0.020). UCRT was resolved within 3 weeks in 13 infants (50.0%), although the thrombosis persisted for up to 2 months in 2 infants (7.7%). We found no significant association between the subclinical UCRT and the neonatal morbidities in preterm infants.

CONCLUSIONS: Though a rare cause of thrombosis, hypercalcemia should be considered in the assessment of infants with subclinical UCRT, and calcium levels should be routinely checked in infants with umbilical catheters.