Very Low Birth Weight Outcomes and Admission Temperature: Does Hyperthermia Matter?

Thermoregulation for very preterm infants in the delivery room: a narrative review

Abnormal temperature in preterm infants is associated with increased morbidity and mortality. Infants born prematurely are at risk of abnormal temperature immediately after birth in the delivery room (DR). The World Health Organization (WHO) recommends that the temperature of newly born infants is maintained between 36.5-37.5oC after birth. When caring for very preterm infants, the International Liaison Committee on Resuscitation (ILCOR) recommends using a combination of interventions to prevent heat loss. While hypothermia remains prevalent, efforts to prevent it have increased the incidence of hyperthermia, which may also be harmful. Delayed cord clamping (DCC) for preterm infants has been recommended by ILCOR since 2015. Little is known about the effect of timing of DCC on temperature, nor have there been specific recommendations for thermal care before DCC. This review article focuses on the current evidence and recommendations for thermal care in the DR, and considers thermoregulation in the context of emerging interventions and future research directions. IMPACT: Abnormal temperature is common amongst very preterm infants after birth, and is an independent risk factor for mortality. The current guidelines recommend a combination of interventions to prevent heat loss after birth. Despite this, abnormal temperature is still a problem, across all climates and economies. New and emerging delivery room practice (i.e., delayed cord clamping, mobile resuscitation trolleys, early skin to skin care) may have an effect on infant temperature. This article reviews the current evidence and recommendations, and considers future research directions.

Risk Factors for Admission Hyperthermia and Associated Outcomes in Infants Born Preterm

Maternal, placental, and neonatal factors were compared between infants born at ≤29 weeks of gestational age with admission hyperthermia (>37.5○C) and euthermia (36.5-37.5○C). Admission hyperthermia was associated with longer duration of face-mask positive-pressure ventilation and infant's temperature ≥37.5○C in the delivery room. Infants born preterm with admission hyperthermia had greater odds of developing necrotizing enterocolitis and neurodevelopmental impairment.

Thermoregulation of the Extremely Low Birth Weight Neonate

The birth of an extremely low birth weight (ELBW) neonate is complex because of their immaturity. Respiratory and hemodynamic stabilization often takes precedence in the immediate delivery period. While establishing effective breathing and circulation is vital to the survival of the neonate, it is crucial to understand that other adverse outcomes can occur during the resuscitation and transport of the ELBW neonate. Impaired thermoregulation is one of the most detrimental adverse outcomes during the golden hour period and later in the neonatal intensive care unit. Hypothermia is an independent risk factor for increased morbidity and mortality and can impact multiple body systems, making management even more challenging. This article discusses the physiology of thermoregulation while exploring interventions to maintain normothermia in the ELBW neonate, ultimately improving long-term outcomes.