Reply to the comment on "Fluid restriction in management of patent ductus arteriosus in Italy: a nationwide survey".

The Authors Chang Liu B.S and Yuan Shi commented our paper on Fluid restriction in management of patent ductus arteriosus (PDA) in Italy. With our study, we conducted a prospective cross-sectional survey among all Italian Neonatal Intensive Care Units (NICUs) to address conservative management of patent ductus arteriosus (PDA) in preterm infants below 29 weeks' gestational age (GA), with specific regard to fluid restriction (FR). The Authors wondered if the heterogeneity of use of fluid restriction both as a prophylactic tool and as a conservative tool when a hemodynamically significant PDA is diagnosed, was due to economic disparities among areas of the included centers. Conducting a secondary analysis of our data, we observed that if we separately consider the responses of two areas, northern and central-southern Italy, FR is slightly more frequently applied in Central and Southern regions (82%) as compared to Northern regions (78%), although this finding does not reach statistical significance. No correlation between the likelihood to adopt conservative measures and the amount of allowed fluid intake was found. The hypothesis that "less fluid intake resulted in milder clinical and echocardiographic presentations of PDA, and thus a lower rate of pharmacological treatment" cannot be supported by our current study design and might deserve future investigations.