Physiological changes in blood flow velocities in the superior mesenteric and coeliac artery in healthy term fetuses and newborns during perinatal period.

Objective: The aim was to describe the course of physiological changes in coeliac artery (CA) and superior mesenteric artery (SMA) blood flow velocities (BFVs) during the perinatal period in healthy term fetuses and infants as it has not been studied in detail so far.

Methods: This prospective Doppler ultrasound study included 50 infants. The examinations were performed in a fetus after the completion of 36.0 gestation weeks before the onset of labor and in infants postnatally at the ages of 2, 24, and 72 h.

Results: The end-diastolic velocity (EDV) in the CA was generally higher than in the SMA (p < 0.001). The EDV in the SMA decreased postnatally (8.4 vs. -7.2, p < 0.001) and showed negative values in 92% of infants. By 24 h of postnatal age, EDV in the SMA had become positive in all of the infants (mean 13.8 cm/s, p < 0.001). The EDV in CA had only positive values. The changes in EDV in both vessels were reflected by changes in the resistance index in inverse manner.

Conclusions: BFV in the CA and SMA changed dramatically in the perinatal period; the most remarkable changes occurred within the first 24 h of life.