Ductal size indexed to weight and body surface area correlates with morbidities in preterm infants ≤32 weeks.

To assess ductal size correlated to spontaneous closure, pharmacological or surgical treatment; to index ductal diameter to body weight and body surface area; to evaluate the morbidities. Retrospective study on preterms ≤32 weeks, birth weight ≤1500 g, extremely low birth weight (ELBW) and very low birth weight (VLBW). Inclusion criteria: patent ductus arteriosus (PDA) with a diameter ≥1 millimeter (mm) at 72 h from birth; need for ibuprofen treatment on the basis of a hemodynamically significant ductus arteriosus (HsPDA). One hundred infants with the diagnosis of PDA have been included. We observed a prevalence of spontaneous closure in 34% of newborns (41.3% VLBW versus 26.7% ELBW). The percentage of response to a single course of ibuprofen was of 62% (68.5% ELBW versus 54.3% VLBW). The mean of absolute ductal diameter was of 2.26 ± 0.62 mm in ELBW and 2.18 ± 0.42 mm in VLBW. The indexing of ductus size to body weight demonstrated a higher value in ELBW than VLBW (2.76 ± 0.97 mm/kg versus 1.84 ± 0.40 mm/kg). Our results confirmed that HsPDA can develop in presence of a ductus >1.5 mm as absolute value or >1.4 mm/kg as indexed to body weight. In ELBW infants the ductal size indexed for body weight and body surface area could be more predictive of spontaneous closure or need for pharmacological treatment compared to the absolute value of ductal size. A strong association between HsPDA and short- or long-term morbidities was confirmed particularly in ELBW.