A nurse is reviewing the laboratory report of a preschooler during a well-child visit. Which of the following laboratory results should the nurse report to the provider?

Choice A rationale:
Lethargy, or extreme fatigue and sluggishness, is a characteristic symptom of hypothyroidism. Hypothyroidism occurs due to an underactive thyroid gland, which leads to a decrease in metabolic activity and energy levels. Children with hypothyroidism often exhibit lethargy, weakness, and a lack of interest in activities. This is due to the reduced metabolic rate and overall slowing down of bodily functions.
Choice B rationale:
Diarrhea is not a common finding associated with hypothyroidism. In fact, hypothyroidism tends to slow down gastrointestinal motility, leading to constipation rather than diarrhea. Therefore, diarrhea is not expected as a symptom in a child with hypothyroidism.
Choice C rationale:
Tachycardia, an elevated heart rate, is not typically associated with hypothyroidism. Instead, hypothyroidism often leads to bradycardia (a slower-than-normal heart rate) due to the overall slowing of the body's metabolic processes.
Choice D rationale:
Hirsutism, which refers to excessive hair growth in areas where hair growth is typically seen in males, is not a common finding in hypothyroidism. Hirsutism is more commonly associated with hormonal imbalances such as polycystic ovary syndrome (PCOS) rather than hypothyroidism.

The correct answer is choice C. 6.8 to 7.7 kg (15 to 17 lb).

Choice A rationale:

This weight range is above the average for a 6-month-old infant. According to growth charts, the 50th percentile weight for a 6-month-old male is approximately 7.9 kg (17 lb 8 oz), and for a female, it’s about 7.3 kg (16 lb 1 oz). Therefore, 8.6 to 9.5 kg would be considered above average and not the anticipated weight for most infants.

Choice B rationale:

This weight range is below the average for a 6-month-old infant. The average weight at 6 months is significantly higher than 4.1 to 5 kg, as infants are expected to double their birth weight by 5 months of age. Therefore, an infant weighing between 9 to 11 lb at 6 months would be considered underweight.

Choice C rationale:

This weight range is within the average for a 6-month-old infant. As mentioned, the 50th percentile weights for 6-month-old infants are approximately 7.9 kg for males and 7.3 kg for females. This choice falls within the expected weight gain trajectory where an infant is anticipated to double their birth weight by 5 months and then gain an additional pound or so by 6 months.

Choice D rationale:

This weight range is significantly above the average for a 6-month-old infant. It is well above the 95th percentile for this age group and would be considered unusual without underlying health conditions that could contribute to such a weight at this age. An infant weighing between 23 to 25 lb at 6 months would be exceptionally rare and likely indicative of an abnormal growth pattern.