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).