Mean levels

Pre-pregnancy (M ± SD)

1^st trimester (M ± SD)

2^nd trimester (M ± SD)

3^rd trimester (M ± SD)

Underweight

57.1 ± 22.5

55.3 ± 26.2

97.1 ± 22.9

86.5 ± 25.6

Normal

110.1 ± 40.4

83.2 ± 44.4

100.4 ± 37.7

37.0 ± 43.1

Overweight

116.8 ± 36.2

85.8 ± 40.9

112.7 ± 29.0

30.0 ± 35.2

Obese

100.8 ± 45.7

81.7 ± 44.4

93.0 ± 26.8

50.0 ± 55.0