A woman who is 8 months pregnant is brought to the emergency department after a serious motor vehicle crash. Although she has no apparent injuries, she is admitted to the hospital for observation for which complication?

Choice A: This is incorrect because lanugo is a fine, downy hair that covers the fetus in utero. It usually disappears by the 36th week of gestation, but it may persist in some preterm infants. Lanugo helps to retain body heat and protect the skin from amniotic fluid. Lanugo is not a sign of postmaturity, but of prematurity or intrauterine growth restriction.

Choice B: This is incorrect because a short, chubby appearance is typical of a term infant, who is born between 37 and 42 weeks of gestation. A term infant has a well-developed subcutaneous fat layer that gives them a rounded shape and smooth skin. A term infant also has a head circumference that is proportional to their body length and weight. A short, chubby appearance is not a sign of postmaturity, but of normal development.

Choice C: This is incorrect because vernix caseosa is a white, cheesy substance that covers the fetus in utero. It usually decreases by the 40th week of gestation, but it may remain in some term infants, especially in the skin folds. Vernix caseosa helps to moisturize and protect the skin from amniotic fluid and infection. Vernix caseosa is not a sign of postmaturity, but of term or near-term gestation.

Choice D: This is the correct answer because cracked, peeling skin is a common sign of postmaturity, which occurs when the infant is born after 42 weeks of gestation. A postmature infant has a loss of subcutaneous fat and water that results in dry, wrinkled, and desquamated skin. A postmature infant also has a large head circumference that is disproportionate to their body length and weight. Cracked, peeling skin indicates prolonged exposure to amniotic fluid and placental insufficiency.

Choice A) Decreased metabolic rate is incorrect because this is not a result of hypothermia in the newborn, but rather a cause of it. Metabolic rate is the speed at which the body uses energy to perform its functions. Newborns have a high metabolic rate, which helps them to maintain a normal body temperature of 36.5°C to 37.5°C (97.7°F to 99.5°F). However, some factors can lower the metabolic rate of newborns, such as prematurity, low birth weight, infection, or hypoglycemia. A low metabolic rate can make the newborn more susceptible to heat loss and hypothermia, which is a condition that occurs when the body temperature drops below 36°C (96.8°F). Therefore, this response is inaccurate and misleading.

Choice B) Decreased oxygen demands is incorrect because this is not a result of hypothermia in the newborn, but rather a consequence of it. Oxygen demand is the amount of oxygen that the body needs to function properly.

Newborns have a high oxygen demand, which helps them to support their growth and development. However, some factors can decrease the oxygen demand of newborns, such as hypothermia, sedation, or asphyxia. A low oxygen demand can impair the oxygen delivery and utilization by the tissues and organs, leading to hypoxia, acidosis, or organ failure. Therefore, this response is irrelevant and inaccurate.

Choice C) Shivering to generate heat is incorrect because this is not a result of hypothermia in the newborn, but rather a mechanism that is absent in them. Shivering is an involuntary contraction of the muscles that produces heat and raises the body temperature. It is a common response to cold exposure in adults and older children, but not in newborns. Newborns do not have the ability to shiver, as their muscles are immature and lack glycogen stores.

Instead, they rely on other methods to generate heat, such as non-shivering thermogenesis, which involves burning brown fat in certain areas of the body. Therefore, this response is irrelevant and inaccurate.

Choice D) Increased glucose demands is correct because this is a result of hypothermia in the newborn that can cause complications. Glucose demand is the amount of glucose that the body needs to produce energy and maintain its functions. Newborns have a high glucose demand, which helps them to support their metabolic rate and thermoregulation. However, some factors can increase the glucose demand of newborns, such as hypothermia, stress, or infection. A high glucose demand can deplete the glucose stores and cause hypoglycemia, which is a low level of glucose in the blood that can lead to seizures, brain damage, or death. Therefore, this response is clear and accurate.