Normal Laboratory Values
Summary
- consider laboratory error if spurious result in well baby
- where possible, use local laboratory reference ranges
- laboratory tests are only useful if they guide management
Introduction
In general, normal values are readily available for healthy term infants. As (extreme) prematurity is a pathological condition in itself, one has to be a little cautious in using the concept of ‘normal’. In most cases, when considering the correction of ‘abnormal’ values, it is wise to consider the following
- is this due to sampling or laboratory error?
- is the baby symptomatic?
- what is the evidence that correcting the abnormality is beneficial?
- is there any risk or danger in correcting an abnormal result?
It is always advisable to keep in mind the reference ranges from your own laboratory as they will be analyser or population specific. This is particularly important with respect to coagulation profiles, for example. If your laboratory does not provide reference ranges for newborns or subsets thereof, the following may be helpful. (N.B. mm/L = micromol/litre). See relevant links for blood glucose and serum bilirubin levels.
|
Value |
Cord |
1-12 hr |
12-24 hr |
24-48 hr |
48-72 hr |
3-10 d |
|
Na (mEq/L) |
147 (126-166) |
143 (124-156) |
145 (132-159) |
148 (134-160) |
149 (139-162) |
|
|
K (mEq/L) |
7.8 (5.6-12) |
6.4 (5.3-7.3) |
6.3 (5.3-8.9) |
6.0 (5.2-7.3) |
5.9 (5.0-7.7) |
|
|
Cl (mEq/L) |
103 (98-110) |
101 (80-111) |
103 (87-114) |
102 (92-114) |
103 (93-112) |
|
|
Ca (millimol/L) |
2.33 (2.1-2.8) |
2.1 (1.8-2.3) |
1.95 (1.7-2.4) |
2.0 (1.5-2.5) |
1.98 (1.5-2.4) |
|
|
Ca (I) (millimol/L) |
1.05-1.37 |
1.05-1.37 |
1.05-1.37 |
1.10-1.44 |
1.20-1.48 |
|
|
PO4 (millimol/L) |
1.8 (1.2-2.6) |
1.97 (1.1-2.8) |
1.84 (0.9-2.6) |
1.91 (1.0-2.8) |
1.87 (0.9-2.5) |
|
|
Mg (millimol/L) |
0.72-1.00 |
0.81-1.05 |
0.78-1.02 |
|||
|
Urea (millimol/L) |
10.4 (7.5-14.3) |
9.6 (2.9-12.1) |
11.8 (3.2-22.5) |
11.4 (4.6-27.5) |
11.1 (5.4-24.3) |
|
|
Creat (millimol/L) |
0.04-0.11 |
0.01-0.09 |
||||
|
CRP (mg/L) |
<7</p/> |
<7</p/> |
<7</p/> |
<7</p/> |
<7</p/> |
<7</p/> |
|
Lactate (millimol/L) |
1.5-4.5 |
0.9-2.7 |
0.8-1.2 |
0.5-1.4 |
||
|
Albumin (g/L) |
28-43 |
28-43 |
28-43 |
28-43 |
28-43 |
30-43 |
|
ALP (IU/L) |
28-300 |
28-300 |
28-300 |
28-300 |
28-300 |
28-300 |
|
T4 |
8.2 (+/-1.8) |
19.0 (+/-2.1) |
19.0 (+/-2.1) |
19.0 (+/-2.1) |
15.9 (+/-3.0) |
|
|
TSH |
3.0-120 |
3.0-30 |
0.3-10 |
|||
|
Cortisol (nanomol/L) |
200-700 |
200-700 |
200-700 |
|||
|
17-OHP (nanomol/L) |
0.7-12.4 |
0.7-12.4 |
||||
|
Hb (g/L) |
168 |
184 |
178 |
170 |
||
|
Hct (%) |
53 |
58 |
55 |
54 |
||
|
MCV |
107 |
108 |
99 |
98 |
||
|
Retic (%) |
3-7 |
3-7 |
1-3 |
0-1 |
||
|
WCC x 109/L |
18.1 (9-30) |
22.8 (13-38) |
18.9 (9.4-34) |
12.2 (5-21) |
||
|
Neutro x 109/L |
11.1 (6-26) |
15.5 (6-28) |
11.5 (5-21) |
5.5 (1.5-10) |
||
|
Lymph x 109/L |
5.5 (2-11) |
5.5 (2-11) |
5.8 (2-11.5) |
5.0 (2-17) |
||
|
Mono x 109/L |
1.1 |
1.2 |
1.1 |
1.1 |
||
|
Eosin x 109/L |
0.4 |
0.5 |
0.5 |
0.5 |
||
|
Platelets (103/mm3 ) |
150-350 |
150-350 |
150-350 |
150-350 |
150-350 |
150-350 |
|
PT (sec) |
11-14 |
11-14 |
11-14 |
11-14 |
11-14 |
|
|
APTT (sec) |
23-35 |
23-35 |
23-35 |
23-35 |
23-35 |
|
|
FBG (mg/dL) |
200-400 |
200-400 |
200-400 |
200-400 |
200-400 |
|
|
Capillary refill |
< 3 seconds |
< 3 seconds |
< 3 seconds |
< 3 seconds |
< 3 seconds |
Acid Base Values* - Term and Preterm infants (by age of life)
|
Value |
Cord |
1-12 hr |
12-24 hr |
24-48 hr |
Range** |
|
pH |
7.33 (UV) |
7.30 (art) |
7.30 (art) |
7.39 |
7.25-7.45 |
|
PCO2 (mmHg) |
43 (UV) |
39 |
33 |
34 |
35-50 |
|
HCO3 (mEq/L) |
21.6 (UV) |
18.8 |
19.5 |
20 |
17-28 |
|
PO2 (mmHg) |
28 (+/-8) (UV) |
62 (+/-13.8) |
68 |
63-87 |
60-80 |
|
Anion gap |
<20</p/> |
<20</p/> |
<20</p/> |
<20</p/> |
8-16 |
* Capillary ranges similar except pO2
** Very difficult to define, wide variation within/between level III Units
Electrolytes - Preterm infants (< 37 weeks) (by day of life)
|
Value |
Day 1 |
Day 3 |
Day 7 |
Day 21 |
Day 35 |
Day 49 |
|
Na (mEq/L) |
140 (133-146) |
140 (133-146) |
140 (133-146) |
136 (129-142) |
137 (133-148) |
137 (133-142) |
|
K (mEq/L) |
5.6 (4.6-6.7) |
5.6 (4.6-6.7) |
5.6 (4.6-6.7) |
5.8 (4.5-7.1) |
5.5 (4.5-6.6) |
5.7 (4.6-7.1) |
|
Cl (mEq/L) |
108 (100-117) |
108 (100-117) |
108 (100-117) |
108 (102-116) |
107 (100-115) |
107 (101-115) |
|
Ca (millimol/L) |
2.3 (1.5-2.9) |
2.3 (1.5-2.9) |
2.3 (1.5-2.9) |
2.4 (2.0-2.8) |
2.4 (2.2-2.6) |
2.4 (2.2-2.7) |
|
Ca (I) (millimol/L) |
0.81-1.41 |
0.72-1.44 |
1.04-1.52 (d5) |
1.04-1.52 |
1.04-1.52 |
1.04-1.52 |
|
PO4 (millimol/L) |
2.5 (1.7-3.5) |
2.5 (1.7-3.5) |
2.5 (1.7-3.5) |
2.4 (2.0-2.8) |
2.3 (1.8-2.6) |
2.2 (1.4-2.7) |
|
Mg (millimol/L) |
0.62-1.02 |
0.66-1.10 |
0.75-1.00 |
0.75-1.00 |
0.75-1.00 |
0.75-1.00 |
|
Urea (millimol/L) |
3.3 (1.1-9.1) |
3.3 (1.1-9.1) |
3.3 (1.1-9.1) |
4.8 (0.8-11.2) |
4.8 (0.7-9.5) |
4.8 (0.9-10.9) |
Other Biochemistry - Preterm infants (by gestation)
|
Value |
27 weeks |
29 weeks |
31 weeks |
33 weeks |
35 weeks |
|
Alb (g/L) |
21-33 |
23-34 |
22-35 |
22-35 |
22-36 |
|
ALP (IU/L) |
35-604 |
119-465 |
112-450 |
110-398 |
113-360 |
|
Creat (micromol/L) day 2 |
0.08-0.16 |
0.07-0.14 |
0.07-0.14 |
0.05-0.13 |
0.05-0.13 |
|
Creat (micromol/L) day 7 |
0.05 -0.11 |
0.04-0.12 |
0.04-0.12 |
0.02-0.11 |
0.02-0.11 |
|
Creat (micromol/L) day 14 |
0.04-0.10 |
0.04-0.10 |
0.04-0.10 |
0.02-0.09 |
0.02-0.09 |
|
Creat (micromol/L) day 21 |
0.03-0.09 |
0.03-0.09 |
0.03-0.09 |
0.02-0.09 |
0.02-0.09 |
|
Creat (micromol/L) day 28 |
0.03-0.08 |
0.02-0.09 |
0.02-0.09 |
0.01-0.06 |
0.01-0.06 |
Haematology - Preterm infants (by age)
|
Value |
Birth |
12 hours |
24 hours |
1 week |
2 weeks |
1 month |
|
Hb (g/L) |
140 (24wks) |
|||||
|
145 (28wks) |
||||||
|
150 (34wks) |
||||||
|
WCC x 109/L |
18.1 (9-30) |
22.8 (13--38) |
18.9 (9.4-34) |
12.2 (5-21) |
11.4 (5-20) |
10.8 (5-19.5) |
|
Neutro x 109/L |
11.1 (6-26) |
15.5 (6-28) |
11.5 (5-21) |
5.5 (1.5-10) |
4.5 (1-9.5) |
3.8 (1-9) |
|
Lymph x 109/L |
5.5 (2-11) |
5.5 (2-11) |
5.8 (2-11.5) |
5 (2-17) |
5.5 (2-17) |
6.0 (2.5-16.5) |
|
Mono x 109/L |
1.1 |
1.2 |
1.1 |
1.1 |
1.0 |
0.7 |
|
Eosin x 109/L |
0.4 |
0.5 |
0.5 |
0.5 |
0.4 |
0.3 |
|
Platelets (103/mm3 ) |
150-350 |
150-350 |
150-350 |
150-350 |
150-350 |
150-350 |
Coagulation Profile - Preterm infants (by age)
|
Value |
Day 1 |
Day 5 |
Day 30 |
|
PT (sec) |
13 (10.6-16.2) |
12.5 (10-15.3) |
11.8 (10-13.6) |
|
APTT (sec) |
53.6 (27-79) |
50.5 (27-74) |
44.7 (27-62) |
|
FBG (g/L) |
2.43 (1.5-3.7) |
2.8 (1.6-4.2) |
2.54 (1.5-4.14) |
CSF - Term and Preterm infants (by age of life)
|
Value |
Term < 7d |
Term > 7d |
Preterm < 7d |
Preterm > 7d |
|
WCC (mm3) |
5 (0-30) |
3 (0-10) |
9 (0-30) |
12 (2-70) |
|
RCC (mm3) |
9 (0-50) |
<10</p/> |
30 (0-333) |
30 |
|
Protein (g/L) |
0.6 (0.3-2.5) |
0.5 (0.2-0.8) |
1 (0.5-2.9) |
0.9 (0.5-2.6) |
|
Glucose (millimol/L) |
3 (1.5-5.5) |
3 (1.5-5.5) |
3 (1.5-5.5) |
3 (1.5-5.5) |
Urine — Term and Preterm infants
|
Value |
Term < 7d |
Term > 7d |
Preterm < 7d |
Preterm > 7d |
|
WCC (per HPF) |
<5</p/> |
<5</p/> |
<5</p/> |
<5</p/> |
|
RCC (per HPF) |
0-2 |
0-2 |
0-2 |
0-2 |
|
Squames (per HPF) |
<5</p/> |
<5</p/> |
<5</p/> |
<5</p/> |
|
Organisms |
Nil |
Nil |
Nil |
Nil |
NB: The Normal Laboratory Values tables are available for printing as a seperate .pdf file. If you do not have a copy of Acrobat Reader to view this file, the latest version is available for free download from www.adobe.com
References
Rennie JM, Roberton NRC (Eds). Textbook of Neonatology, 3rd Ed. Churchill Livingstone, Edinburgh, 1999.
Taeusch HW, Ballard RA (Eds). Avery’s Diseases of the Newborn 7th Ed. W.B. Saunders Company, Philadelphia. 1998
Other Reading/Web links
Forfar JO. Normal and abnormal calcium, phosphorus and magnesium metabolism in the perinatal period. Clinics in Endocrinol and Metab 1976;5:123-48
Kuhne T, Imbach P. Neonatal platelet physiology and pathophysiology. Eur J Pediatr 1998;157:87-94
Hajjar FM. Neutrophils in the newborn: Normal characteristics and quantitative disorders. Sem Perinatol 1990;14:374-83
Strozik KS, Pieper CH, Roller J. Capillary filling time in newborn babies: normal values. Arch Dis Child 1997;76:F193-6
Buchanan G. Neonatal coagulation: Normal physiology and pathophysiology. Clin Haematol 1978;7:85-109
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