You are called to the nursery to evaluate a newborn infant. The mother is a 24-year-old primigravida. Her pregnancy was complicated by preeclampsia. The infant was delivered at 39-weeks gestation via emergent cesarean section due to maternal hypertension and non-reassuring fetal heart tones. On examination, the infant's weight is 2.6 kg (5 lb 11 oz) placing him in the 5^th percentile, height is 18 inches (46 cm) placing him in the 5^th percentile, and head circumference is 13 inches (33 cm) placing him in the 10^th percentile. The infant's head seems large for his body. There is a paucity of subcutaneous fat. The remainder of the physical examination is unremarkable. This infant is at risk for having (or developing) which of the following?

Question

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Infants are labeled small for gestational age (SGA) when their birth weight is below the 10^th percentile for gestational age. Both maternal and fetal factors can lead to abnormal fetal growth. Maternal factors include preeclampsia, malnutrition, placental insufficiency, multiparity, or drug use. Fetal factors include genetic factors, chromosomal abnormalities, congenital infections, or inborn errors of metabolism. These low birth weight infants usually have intrauterine growth restriction, which can be symmetrical (height, weight, and head circumference are all equally affected) or asymmetrical (weight is affected more than height and head circumference). ^th Infants who are small for gestational age are at risk for several complications due to their size, including hypoxia, perinatal asphyxia, meconium aspiration, hypothermia, hypoglycemia, hypocalcemia, and polycythemia. The polycythemia results from increased erythropoietin secretion in response to fetal hypoxia. (Choice A) Large for gestational age infants are at risk for developing hip subluxation and talipes calcaneovalgus primarily due to intrauterine deformation. Small for gestational age infants usually do not develop these abnormalities. (Choice C) Hypoglycemia is commonly seen in small for gestational age infants due to decreased glycogen stores. Often, the hypoglycemia can be managed with early and frequent feeds. Infants with very low birth weights can have hyperglycemia due to low insulin secretion, but hypoglycemia would be more likely in an infant weighing 2.6 kg. (Choice D) SGA infants have decreased subcutaneous fat and therefore impaired thermoregulation. As a result, these infants often become hypothermic. (Choice E) Most SGA infants have hypocalcemia, which is thought to be caused by a decreased transfer of calcium across the placenta. Hypercalcemia, however, is not seen. Educational objective: Small for gestational age infants have a weight under the 10^th percentile for gestational age at birth and may have complications such as hypoxia, polycythemia, hypoglycemia, hypothermia, and hypocalcemia. ^th

You Are Called to the Nursery to Evaluate a Newborn