BACKGROUND & AIMS: In preterm and sick newborn infants, peripherally inserted central catheters (PICC) are used for the delivery of concentrated parenteral nutrition and other high risk drugs. Despite the precaution issued by the ESPGHAN 2018, heparin is used in many neonatal intensive care units (NICU) and is thought to extend PICC usability. This study aimed to examine the association of prophylactic heparin with elective PICC removal rates, with complication rates and dwell-times. METHODS: All PICCs placed at two different Level III NICUs during 2017, were analyzed retrospectively. Out of 168 PICCs, 36 had to be excluded, leaving 132 PICCs for analysis. Prophylactic heparin was used in 90 PICCs (heparin-group) and 42 PICCs without (control group) RESULTS: Sixty-six PICCs (73%) vs 30 (71%) could be removed electively in the heparin-group (adjusted Odds Ratio 95% confidence interval (CI) 0.95 [0.31, 2.89], p>
0.9). Complications occurred in 17 (19%) and 8 (19%) PICCs in the heparin-group and control-group, respectively. Dwell-times did not differ significantly with median 10 days (Interquartile range (IQR) 6,17) in the heparin-group and 8 days (IQR 7,12) in the control-group with an adjusted hazard ratio 0.70 (95% CI [0.45, 1.09], p=0.11). CONCLUSION: In our retrospective analysis, adding heparin to admixtures infused via PICCs did not alter the odds of elective removals or complication rates. Furthermore, Dwell-times did not differ significantly between the two groups. In line with the ESPGHAN recommendations, our data can not support the use of heparin to improve PICC usability.