Table 1 Demographics of subjects included in analysis

Maternal variables

Age at enrollment (mean (SD))

27.11 (6.26)

26.62 (5.28)

0.591

Education level (%)

0.205

Less than high school

19 (23.8)

14 (17.9)

High school degree/ GED

25 (31.2)

37 (47.4)

Some college

32 (40.0)

25 (32.1)

Bachelor’s degree (BA, BS)

4 (5.0)

2 (2.6)

BMI at enrollment (mean (SD))

30.45 (7.68)

28.84 (6.57)

0.16

Gravida (mean (SD))

3.55 (2.38)

3.29 (2.19)

0.485

Maternal asthma (%)

26 (32.5)

26 (33.3)

1

Study variables

Site (%)

0.93

OHSU

13 (16.2)

13 (16.7)

SWW

37 (46.2)

38 (48.7)

IA

30 (37.5)

27 (34.6)

GA at randomization > 18 weeks (%)

40 (50.0)

48 (61.5)

0.194

Plasma vitamin C in pregnancy

Randomization (mean (SD))

13

47.59 (17.65)

48.18 (20.18)

0.848

Mid-gestation (mean (SD))

8

39.71 (19.04)

59.38 (23.35)

 < 0.001

Late-gestation (mean (SD))

29

37.87 (15.27)

51.62 (22.48)

 < 0.001

Smoking variables

Cigarettes per day (mean (SD))

8.06 (5.12)

7.59 (4.53)

0.54

Pack yrs (mean (SD))

11.24 (9.46)

10.63 (8.31)

0.671

Plasma cotinine (ng/ml)

Randomization (mean (SD))

17

67.87 (44.97)

83.73 (56.41)

0.061

Mid-gestation (mean (SD))

12

75.04 (126.91)

68.60 (51.20)

0.682

Late-gestation (mean (SD))

38

61.80 (44.57)

61.18 (36.48)

0.93

Maternal hair nicotine (ng/mg)

Randomization (median [IQR])

19

2.68 [0.68, 6.39]

3.20 [1.27, 9.84]

0.171

Delivery (median [IQR])

35

1.50 [0.71, 5.57]

2.14 [1.23, 4.60]

0.239

Postpartum 3 months (median [IQR])

14

3.41 [1.03, 7.90]

3.30 [1.25, 8.07]

0.807

Postpartum 12 months (median [IQR])

30

4.58 [1.58, 9.79]

4.72 [2.01, 9.53]

0.551

Postpartum 48 months (median [IQR])

24

1.29 [0.34, 3.97]

2.10 [0.67, 3.92]

0.125

Postpartum 60 months (median [IQR])

14

1.85 [0.41, 4.30]

1.82 [0.67, 3.43]

0.588

Child hair nicotine (ng/mg)

Delivery (median [IQR])

85

0.37 [0.17, 0.69]

0.30 [0.18, 0.73]

0.973

Postnatal 3 months

21

2.54 [1.63, 6.64]

3.64 [2.17, 6.89]

0.155

Postnatal 12 months

23

1.60 [0.74, 4.53]

2.06 [1.02, 4.07]

0.205

Postnatal 48 months

15

0.33 [0.14, 1.80]

0.58 [0.13, 1.53]

0.638

Postnatal 60 months

8

0.34 [0.08, 1.18]

0.35 [0.13, 0.79]

0.86

Infant variables

GA at birth (mean (SD))

38.61 (1.63)

38.73 (1.83)

0.685

Preterm (%)

4 (5.0)

9 (11.5)

0.228

White (%)

65 (81.2)

59 (75.6)

0.507

Sex = Female (%)

42 (52.5)

36 (46.2)

0.523

Child variables at 5YO Visit

PFT height (mean (SD))

113.15 (5.78)

112.52 (4.88)

0.456

FEF_25–75(L/sec) (mean (SD))

1.28 (0.31)

1.47 (0.37)

 < 0.001

FEF₅₀ (L/sec) (mean (SD))

1.44 (0.34)

1.62 (0.38)

0.002

FEF₇₅ (L/sec) (mean (SD))

0.64 (0.19)

0.79 (0.26)

 < 0.001

FEV₁ (L/sec) (mean (SD))

1.13 (0.19)

1.15 (0.19)

0.403

FEV₁/FVC (mean (SD))

86.56 (5.77)

90.15 (6.70)

 < 0.001

Wheeze at 4–6 yrs of age = Yes (%)

39 (48.8)

22 (28.2)

0.013