A prospective cohort study using non-invasive methods of cardiovascular assessment to compare postnatal adaptation in well late preterm and term infants.

Echocardiography was combined with pulse oximetry plethysmography to investigate postnatal cardiovascular adaptation in late preterm and term infants. Median (IQR) pleth variability decreased over three days and similar, day2 15%(12-18%) preterm versus 16%(15-18%) term infants. Median (IQR) pulse transit time heart rate normalised was lower in term babies, day2 0.55(0.51-0.63) versus 0.64(0.62-0.68).