Background: Central blood flow measurements can provide more detailed information on the haemodynamic condition of the preterm infant. However, normal values for right ventricular output (RVO) and left ventricular output (LVO) and superior vena cava (SVC) flow are only available during the transitional phase (48 h).

Objective: The aim of this study is to collect normal values for RVO, LVO and SVC flow after the transitional phase in healthy preterm infants.

Methods: RVO, LVO and SVC flow were measured with functional echocardiography on day 7 and day 14 in preterm infants less than 32 weeks. Infants with a large patent ductus arteriosus, an atrial shunt or with an intercurrent disease and infants treated with artificial ventilation, continuous positive airway pressure with >30% oxygen, inotropes or other cardiovascular support were excluded

Results: We performed 31 and 29 measurements on, respectively, days 7 and 14 in a total of 41 infants with a median gestational age (range) of 29 weeks (25–31). RVO and LVO values were higher and SVC flow was comparable with previously published data. There were no significant differences between days 7 and 14 of life (table).

Conclusions: Normal values for RVO and LVO flow but not SVC flow seem to be higher in the first weeks of life compared with the transitional phase in healthy preterm infants. Furthermore, these flow variables seem to remain stable over time.