Comparison of different body temperature measurement methods in the neonatal intensive care unit and subgroup analysis according to gestational age.

OBJECTIVE

This study aimed to compare rectal, axillary, tympanic, and non-contact forehead temperature measurements in neonates monitored in the neonatal intensive care unit and to evaluate these methods according to gestational age.

MATERIALS AND

METHODS

This prospective observational study was conducted in the Neonatal Intensive Care Unit of Van Yüzüncü Yıl University Dursun Odabaş Medical Center between November 2025 and February 2026. A total of 126 neonates whose clinical condition was suitable for temperature measurement using four different methods were included in the study. Rectal, axillary, tympanic, and non-contact forehead temperatures were measured sequentially by the same researcher. Differences between measurement methods were evaluated using the paired-samples t-test, while comparisons among gestational age groups were analyzed using ANOVA or the Kruskal-Wallis test, as appropriate. Agreement among methods was assessed by Bland-Altman analysis, correlation analysis, and regression analysis.

RESULTS

The mean gestational age of the enrolled neonates was 34.2 ± 4.1 weeks. Mean temperature values were 37.25 ± 0.40 °C for rectal measurements, 36.41 ± 0.37 °C for axillary measurements, 37.02 ± 0.37 °C for tympanic measurements, and 36.70 ± 0.10 °C for non-contact forehead measurements. Rectal temperature values were significantly higher than those obtained by all other methods. No significant differences in measurement methods were observed among gestational age groups. The smallest mean difference compared with rectal measurements was observed with tympanic measurements. The correlation and regression performance of non-contact forehead measurements were lower.

CONCLUSION

Tympanic measurement appears to be the closest alternative to rectal temperature measurement; however, none of the non-invasive methods demonstrated a level of agreement sufficient to completely replace rectal measurements.