North American Registry of Midwives (NARM) Practice Exam

What activates non-shivering thermogenesis in newborns?

1. Environmental temperature

2. Gestational age

3. Nutrition intake

4. Emotional response

The correct answer is: Gestational age

Non-shivering thermogenesis in newborns is primarily activated by gestational age. This process is crucial for maintaining body temperature in neonates, especially in the first few days after birth when they are particularly vulnerable to hypothermia. Brown adipose tissue (BAT), which is present in newborns, is responsible for non-shivering thermogenesis. The amount and function of this brown fat increase with gestational age; therefore, full-term infants have a better capacity for non-shivering thermogenesis compared to preterm infants who may have less brown fat and immature metabolic systems. While environmental temperature can influence temperature regulation, it is not the direct activator for non-shivering thermogenesis itself; rather, it plays a role in the overall thermal environment for the infant. Nutrition intake, although important for overall metabolism and energy production, does not directly activate non-shivering thermogenesis. Emotional responses are associated with many physiological processes but do not specifically trigger this thermogenic mechanism in newborns. Therefore, understanding the developmental aspect of gestational age provides clarity on the mechanisms of thermoregulation in infants.