African American infant is seen at 36 hours of life by the neonatologist for routine care. The infant was born at term by Cesarean due to failure to progress to a 33-year-old woman whose pregnancy was complicated by scant prenatal care and poorly controlled gestational diabetes.
Apgar scores were 5 and 8 at 1 and 5 minutes, respectively. Birth weight was 4200 g (10 lb, 12 oz).The hospital course has been notable for an initial glucose in the normal newborn nursery of 34 mg/dL which improved to 52 mg/dL after breast-feeding.
The infant has been breast feeding well every 2½ to 3 hours and has voided but has not yet stooled. The initial examination at approximately 18 hours of life was normal. On current physical examination, the Temperature is 37°C (98.6°F), heart rate 144 beats/min, respiratory rate 30 breaths/min, and blood pressure 99/68 mm Hg. She is asleep but easily arousable. Height, weight, and head circumference are at the 95th percentile. Skin is slightly icteric.The head is normocephalic without lesions. Mucous membranes are moist, pink, and without lesions. The chest is clear.
The heart has a normal S1 and S2 without murmur. The abdomen is soft, full in appearance, and nontender. No hepatosplenomegaly is noted. The rectum and vagina are patent.
Which of the following is the current diagnosis of most concern?
A. Polycythemia
B. Hypocalcemia
C. Small left colon syndrome
D. Cystic fibrosis
E. Caudal regression syndrome