Neonatal hypothermia in Tehran, Iran: incidence, severity and death rate

ABSTRACT

In 1958, Silverman demonstrated that maintenance of body temperature reduces mortality in low birth weight infants. From the early 1990s it was already recognized that adequate environmental warmth was essential in the case of newborns. However, neonatal hypothermia continues to be a significant issue in developing countries.In order to describe the incidence and severity of hypothermia after delivery and to determine the possibility of related mortality risk among neonates in a tertiary nursery, we measured the body temperature on admission of 898 consecutive inborn infants after birth by a low-reading thermometer. Body temperature less than 36.5°C was designated as 'hypothermia'. In such cases the infants were re-warmed according to WHO recommendations. Their body temperature was checked and recorded every hour and their final outcome was noted.The overall incidence of hypothermia was 53.2%. 456 [i.e., 50.2% of] infants had mild hypothermia [35>T>36.5] while 22 [2.5%] of them had moderate to severe hypothermia [T<35°C]. The incidence and severity of hypothermia was found to be significantly associated with birth weight [p= 0.000] and gestational age [p= 0.000]. The duration of re-warming was also correlated with birth weight [p= 0.000]. Logistic regression analysis showed that the mortality rate of hypothermic neonates is 3.64 times that of the normotherms. The risk of death was higher in the moderate to severe hypothermic groups than in the mild hypothermic infants.In our study, the incidence of hypothermia was found to be high with both the incidence and severity to be significantly associated with birth weight and gestational age. The risk of death was recognized to be higher in the hypothermic new borns than non-hypothermic ones