Comparison of lung functions of healthy late preterm newborns with the term newborns

This study aimed to compare the lung functions of healthy late preterm babies when they reach term with the lung functions of healthy term babies. Tidal breathing analysis (MasterScreen™ pediatric PAED) was applied to late preterm (340/7-366/7) and term babies (>37 0/7) born between December 2021 and December 2023 at their corrected 40th week. Babies who did not need oxygen after birth or who received oxygen support or nasal CPAP support for less than 12 hours and whose birth weight and height were between the 10th and 90th percentile according to the week of birth were included in the study. Cases with maternal smoking, respiratory distress, congenital anomaly, sepsis and APGAR score <8 were excluded from the study. A total of 120 babies (50% male), including 60 late preterm and 60 term babies, were included in the study. The average birth weights of preterm and term babies were 2462  337 g and 3293  335 g, respectively. The average birth weeks were 35 and 39 weeks. The average respiratory rate of late preterm babies was found to be significantly higher than that of term babies (p=0.036). In tidal breath analysis, mean TPTEF/TE (the ratio of the time from the beginning of expiration to the peak flow point to the total expiratory time) and mean VPTEF/VE (the ratio of the volume from the beginning of expiration to the peak flow point to the total expiratory volume) were significantly lower in late preterm babies than in term babies ( p=0.003 and p=0.004 respectively). Although the mean tidal volume was observed to be lower in late preterms, there was no difference between the two groups. When tidal breath analysis parameters were evaluated according to gender, no difference was observed between the TNA parameters of term and preterm babies (p>0.05). In our study, data on physiological lung development of late preterm and term newborns and reference values in tidal breathing analysis are presented; It has been shown that the respiratory functions of late preterm babies at their corrected 40th week are different from the respiratory functions of term babies. Keywords: Tidal Breath Analysis, Newborn, Preterm, Term, Pulmonary Function