Table 2 Laboratory Reference Intervals by gestational age for phosphate, calcium, albumin-adjusted calcium, magnesium (mmol/L), and alkaline phosphatase (units/L)

23-27

51

2.1

0.3

1.6

2.6

28-31

119

2.0

0.3

1.4

2.7

32-34

191

2.0

0.2

1.5

2.5

35-36

119

2.0

0.3

1.4

2.6

> 36 weeks (term)

52

1.8

0.2

1.4

2.3

Calcium (mmol/L)

23-27

51

2.5

0.2

2.0

3.0

28-31

115

2.6

0.3

2.0

3.1

32-34

176

2.6

0.2

2.2

3.1

35-36

110

2.6

0.3

2.1

3.1

> 36 weeks (term)

52

2.7

0.1

2.5

3.0

Albumin-adjusted Calcium (mmol/L)

23-27

49

2.7

0.2

2.2

3.2

28-31

109

2.7

0.3

2.2

3.3

32-34

175

2.8

0.2

2.3

3.2

35-36

116

2.7

0.2

2.3

3.2

> 36 weeks (term)

51

2.8

0.1

2.6

3.0

Magnesium (mmol/L)

23-27

48

0.79

0.07

0.65

0.94

28-31

127

0.79

0.10

0.58

0.99

32-34

193

0.76

0.08

0.60

0.92

35-36

120

0.76

0.09

0.58

0.93

> 36 weeks (term)

53

0.77

0.08

0.63

0.92

Alkaline Phosphatase (units/L)

23-27

50

201

61

80

321

28-31

130

196

68

61

330

32-34

197

174

55

66

283

35-36

123

166

56

57

275

> 36 weeks (term)

52

159

49

62

256