2016 Volume 65 Issue 5 Pages 500-504
The normal reference ranges of biochemical parameters in newborn infants still remains controversial. One reason for such controversy is the large individual differences. We considered that the individual differences are related to gestational age. Therefore, we divided our subjects into three groups: 22–27 weeks, 28–36 weeks, and 37–41 weeks of gestational age. We determined the clinical reference ranges of 15 biochemical parameters in newborn infants at our hospital. However, we eliminated abnormal analysis data with a clear cause. The age ranges were 0–6 days and 7–27 days after birth. We examined the usefulness of grouping based on gestational age. There was a significant difference in the mean among the three groups. The clinical reference ranges that disregard gestational age were different among the three groups in all the tests. Total protein level was a perfect example showing the difference. At 0–6 days after birth, the range obtained from infants of 22–27 weeks of gestational age was 3.0–5.3 g/dL, whereas that obtained from infants of 37–41 weeks of gestational age was 4.2–6.5 g/dL. Considering the gestational age is useful for estimating the reference range for newborn infants.
