Hypothermia in neonates

The neonate is at high risk of hypothermia, particularly if premature, small for dates, or sick.

At delivery the wet surface of an infant increases the heat loss to at least 0.25øC per minute. It is for this reason that a priority of resuscitation is that the child is dried, wrapped, and managed under a warmer.

Methods available to the neonate to preserve heat include adoption of a flexed posture, subcutaneous fat insulation, and active thermogenesis by brown adipose. The more premature or underweight a baby the less these methods are available.

The preterm neonate has a poor thermoregulatory balance for several reasons:

• neural feedback control is not finely tuned
• high surface area to volume ratio
• the skin is not fully developed until 29 weeks of age
• preterm infants especially have low brown fat reserves along the scapula and paravertebral gutter