Cold Stress in Newborns


Thermoregulation is an essential aspect of neonatal care. Newborns that are least able to tolerate hypothermia include the preterm, growth restricted infant and those with asphyxia or respiratory difficulties. Preterm newborns have an impaired ability to prevent heat loss and to increase their body heat production in response to low environmental temperatures.

The risk of cold stress is greatest during the immediate transitional period after delivery and is caused by the preterm newborn’s immature skin, the high ratio of surface area to birth weight, and the environmental conditions in the delivery room (large temperature gradients between the newborn’s body temperature and the ambient temperature of delivery room, air flow through the room, and contact with cold surfaces that lead to significant evaporative, radiant, convective, and conductive heat losses).

Consequences of Cold Stress

Decreased body temperature (hypothermia) results to cold stress. Cold stress in response causes many body changes. The consequences of cols stress are the following:

  • Increased Metabolic Rate

Result: Decreased Surfactant Production and hypoxemia leading to respiratory distress

When the metabolic rate of a neonate is increased, the need for oxygen also increases. A 2 degree centigrade drop in environmental temperature can double the newborn’s oxygen need. As cold stress progresses, surfactant production also diminish thereby impeding lung expansion. As a result hypoxemia will be noted and mild respiratory distress can become severe hypoxia if oxygen must be used for heat production.

  • Increased Metabolic Rate

Result: Increase consumption of glucose resulting to hypoglycemia

When the metabolic rate rises for the body to produce heat, glucose requirement also increases. As the demand of glucose surges the body compensates to this need by converting glycogen stores to glucose. When glycogen stores are converted to glucose, they may be quickly used up resulting to hypoglycemia.

  • Increased Metabolic Rate

Result: Failure to gain weight

Infants who must use glucose for temperature regulation and maintenance have less available supply for growth and development.

  • Metabolism of brown fat

Result: Metabolic Acidosis; increases the risk of jaundice

When brown fats are metabolized in the presence of insufficient oxygen supply increased acid production will result. Rising amount of acids causes metabolic acidosis, which can be a life-threatening condition.  Aside from that, elevated fatty acids in the blood can interfere with the transport of bilirubin to the liver for conjugation, thus, increasing the risk of jaundice in a newborn.

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Daisy Jane Antipuesto RN MN

Currently a Nursing Local Board Examination Reviewer. Subjects handled are Pediatric, Obstetric and Psychiatric Nursing. Previous work experiences include: Clinical instructor/lecturer, clinical coordinator (Level II), caregiver instructor/lecturer, NC2 examination reviewer and staff/clinic nurse. Areas of specialization: Emergency room, Orthopedic Ward and Delivery Room. Also an IELTS passer.

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