Reference Ranges During Pregnancy

Clinical
Biochemistry

Analyte 12 wks 24 wks 36 wks Non-pregnant Units

Sodium 131 - 139 133 - 139 133 - 139 136 - 142 mmol/l

Potassium 3.3 - 4.8 3.3 - 4.8 3.3 - 4.8 3.5 - 5.0 mmol/l

Chloride 99 - 109 99 - 109 99 - 109 99 - 109 mmol/l

Bicarbonate 18 - 26 18 - 26 18 - 26 22 - 29 mmol/l

Urea 1.6 - 5.0 1.6 - 4.3 0.9 - 4.5 2.5 - 6.5 mmol/l

Creatinine 25 - 80 25 - 75 22 - 93 50 - 90 µmol/l

Albumin 33 - 43 29 - 37 28 - 36 36 - 46 g/l

Alkaline phosphatase 20 - 90 30 - 100 70 - 270 35 - 100 U/l

Urate 70 - 250 115 - 250 145 - 360 155 - 320 µmol/l

Data is based on "Clinical Biochemistry of Pregnancy" by G Lockitch in Clinical Laboratory Sciences, 34(1);67-139(1997).

Analyte	12 wks	24 wks	36 wks	Non-pregnant	Units
Sodium	131 - 139	133 - 139	133 - 139	136 - 142	mmol/l
Potassium	3.3 - 4.8	3.3 - 4.8	3.3 - 4.8	3.5 - 5.0	mmol/l
Chloride	99 - 109	99 - 109	99 - 109	99 - 109	mmol/l
Bicarbonate	18 - 26	18 - 26	18 - 26	22 - 29	mmol/l
Urea	1.6 - 5.0	1.6 - 4.3	0.9 - 4.5	2.5 - 6.5	mmol/l
Creatinine	25 - 80	25 - 75	22 - 93	50 - 90	µmol/l
Albumin	33 - 43	29 - 37	28 - 36	36 - 46	g/l
Alkaline phosphatase	20 - 90	30 - 100	70 - 270	35 - 100	U/l
Urate	70 - 250	115 - 250	145 - 360	155 - 320	µmol/l