Objective: To reveal the incidence of umbilical artery catheter-related thrombosis (UACRT), the associated risk factors and the natural history of clot formation and regression.
Study design: A prospective cohort study. An umbilical artery catheter was inserted in 61 infants, who were evaluated and followed by serial duplex ultrasound studies for the development of UACRT, renal artery resistance index (RI) and clot resolution. Maternal and infant clinical variables were correlated with the characteristics of thrombi.
Result: Nineteen infants developed UACRT, all resolved spontaneously without sequella; most had maximal length at the first evaluation. No correlation was found between the thrombus length and time to resolution. The RI did not differ between the infants with and without UACRT. After adjusting for possible confounding, catheter days was the only covariate associated with UACRT.
Conclusion: Asymptomatic UACRT in our cohort was a self-resolving disease; it was associated with catheter days and did not necessitate medical treatment.