Table 1_Neonatal admission hypothermia and early postnatal growth in a tertiary neonatal unit in Botswana: a prospective observational study.docx

Introduction

Neonatal hypothermia is independently associated with higher morbidity and mortality and remains under-recognized and inconsistently managed in many low-resource neonatal units. Although thermal-care interventions are well established, the relationship between admission temperature and early postnatal growth has been insufficiently described, particularly in sub-Saharan African tertiary neonatal units.

Methods

We conducted a secondary retrospective analysis of a prospective observational study of neonates admitted to a tertiary public neonatal unit in Gaborone, Botswana, from 1 January 2020 to 31 December 2021. Admission hypothermia was defined as a first recorded axillary temperature <36.5°C and classified according to World Health Organization criteria. Growth outcomes included maximal weight loss from birth weight, age at nadir weight, age at regained birth weight, and weekly average weight gain following nadir weight. Multivariable linear regression models assessed associations with admission hypothermia, adjusting for sex, birth weight, gestational age, feeding practices, kangaroo mother care, and disposition.

Results

Among 1,358 neonates, admission hypothermia was common, affecting 66.5% (n = 903), with moderate hypothermia accounting for the majority of these cases. The mean (SD) maximal weight loss was 6.75% (5.90%), nadir weight occurred at 4.26 (4.19) days of life, and birth weight was regained at 9.45 (7.61) days of life. Admission hypothermia was not independently associated with these growth outcomes. Gestational age, however, was consistently associated with early growth: older gestational age was associated with lower maximal weight loss, earlier nadir weight, earlier regained birth weight, and shorter time to discharge or transfer among survivors.

Conclusion

In this large prospective cohort from Botswana, admission hypothermia was highly prevalent but was not independently associated with early postnatal growth outcomes. Gestational age was the strongest predictor of early postnatal growth trajectories, highlighting the disproportionate vulnerability of premature infants and the importance of optimizing nutritional and supportive care strategies during early hospitalization.