Neonatal colour Doppler ultrasound study: normal values of abdominal flow velocities in the neonate during the first month of life

BACKGROUND: Doppler US to measure abdominal blood flow velocities (ABFV) is increasingly used to investigate intestinal haemodynamics in several clinical conditions in neonates. Studies that provide reference values of ABFV during the entire neonatal period are currently lacking. OBJECTIVE: To make available normal reference values of ABFV and Doppler indices in the coeliac trunk and superior mesenteric artery during the first month of life in term and healthy preterm infants. MATERIALS AND METHODS: ABFV were obtained with colour Doppler US in 69 neonates (12 term, 57 preterm) divided into four gestational age groups (25-28 weeks, 29-32 weeks, 33-36 weeks, and 37-41 weeks). RESULTS: ABFV increased with increasing gestational and postnatal age. We also provide normal reference values of ABFV and Doppler indices to compare with measurements of abdominal blood flow changes during the neonatal period for diagnostic, therapeutic and prognostic purposes. CONCLUSION: These longitudinal reference values provide a useful tool for assessing possible alteration in ABFV secondary to neonatal pathologies.