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Table 2 Descriptive statistics by maternal smoking in pregnancy classification

From: A novel approach to risk exposure and epigenetics—the use of multidimensional context to gain insights into the early origins of cardiometabolic and neurocognitive health

 

Non-smoker

Non-sustained

Sustained

Unknown

Total

p value

Total

N = 8754

N = 963

N = 3713

N = 1781

N = 15,211

 

Sex

     

0.022

 N-Miss

22

1

7

487

517

 

 Male

4460 (51.1%)

476 (49.5%)

1987 (53.6%)

650 (50.2%)

7573 (51.5%)

 

 Female

4272 (48.9%)

486 (50.5%)

1719 (46.4%)

644 (49.8%)

7121 (48.5%)

 

Ethnicity

     

 < 0.001

 N-Miss

165

21

122

683

991

 

 Caucasian

8166 (95.1%)

891 (94.6%)

3369 (93.8%)

981 (89.3%)

13,407 (94.3%)

 

 Other

423 (4.9%)

51 (5.4%)

222 (6.2%)

117 (10.7%)

813 (5.7%)

 

Gestational age

     

 < 0.001

 N-Miss

2

0

1

589

592

 

 Mean (SD)

39.3 (2.4)

39.5 (2.1)

39.2 (2.5)

28.0 (13.8)

38.4 (5.5)

 

 Range

9.0—44.0

18.0—47.0

10.0—46.0

4.0—45.0

4.0—47.0

 

Birth weight, internal z-score

     

 < 0.001

 N-Miss

162

12

80

793

1047

 

 Mean (SD)

0.0 (0.5)

0.1 (0.5)

-0.1 (0.5)

-0.1 (0.5)

0.0 (0.5)

 

 Range

-4.4

-3.9

-3.8

-3.8

-4.4

 

Birth length, internal z-score

     

 < 0.001

 N-Miss

245

26

132

813

1216

 

 Mean (SD)

0.1 (1.6)

0.4 (1.6)

-0.3 (1.6)

-0.1 (1.4)

0.0 (1.6)

 

 Range

-14.8

-12

-13.7

-9.9

-14.8

 

Gestational weight gain

     

 < 0.001

 N-Miss

1937

235

1148

1608

4928

 

 Over

1771 (26.0%)

277 (38.0%)

714 (27.8%)

48 (27.7%)

2810 (27.3%)

 

 Recommended

2749 (40.3%)

278 (38.2%)

912 (35.6%)

66 (38.2%)

4005 (38.9%)

 

 Under

2297 (33.7%)

173 (23.8%)

939 (36.6%)

59 (34.1%)

3468 (33.7%)

 

Maternal grandmother—ever smoked

 N-Miss

455

29

232

1781

2497

 

 False

4280 (51.6%)

562 (60.2%)

2373 (68.2%)

0

7215 (56.7%)

 

 True

4019 (48.4%)

372 (39.8%)

1108 (31.8%)

0

5499 (43.3%)

 

Maternal grandmother—smoked while pregnant

 N-Miss

496

32

245

1781

2554

 

 Don’t know

1178 (14.3%)

152 (16.3%)

514 (14.8%)

0

1844 (14.6%)

 

 False

5543 (67.1%)

610 (65.5%)

1709 (49.3%)

0

7862 (62.1%)

 

 True

1537 (18.6%)

169 (18.2%)

1245 (35.9%)

0

2951 (23.3%)

 

Maternal grandfather—ever smoked

 N-Miss

297

37

396

1781

2511

 

 False

6383 (75.5%)

482 (52.1%)

1064 (32.1%)

0

7929 (62.4%)

 

 True

2074 (24.5%)

444 (47.9%)

2253 (67.9%)

0

4771 (37.6%)

 

Mother’s partner—smoked while pregnant

 N-Miss

290

12

195

1781

2278

 

 False

8125 (96.0%)

863 (90.7%)

3032 (86.2%)

0

12,020 (92.9%)

 

 True

339 (4.0%)

88 (9.3%)

486 (13.8%)

0

913 (7.1%)

 

Others who smoke in household

 N-Miss

554

45

342

1781

2722

 

 False

5992 (73.1%)

731 (79.6%)

2799 (83.0%)

0

9522 (76.2%)

 

 True

2208 (26.9%)

187 (20.4%)

572 (17.0%)

0

2967 (23.8%)

 

Maternal education level at time of pregnancy

     

 < 0.001

 N-Miss

531

76

508

1534

2649

 

 Non-degree

7359 (89.5%)

763 (86.0%)

2464 (76.9%)

192 (77.7%)

10,778 (85.8%)

 

 Other

864 (10.5%)

124 (14.0%)

741 (23.1%)

55 (22.3%)

1784 (14.2%)

 

Maternal financial concerns

     

 < 0.001

 N-Miss

755

105

618

1581

3059

 

 No strain

7445 (93.1%)

777 (90.6%)

2558 (82.6%)

163 (81.5%)

10,943 (90.1%)

 

 Other

554 (6.9%)

81 (9.4%)

537 (17.4%)

37 (18.5%)

1209 (9.9%)

 

Maternal psychopathology

     

 < 0.001

 N-Miss

246

41

185

1580

2052

 

 Denies

6749 (79.3%)

644 (69.8%)

2188 (62.0%)

141 (70.1%)

9722 (73.9%)

 

 Other

1759 (20.7%)

278 (30.2%)

1340 (38.0%)

60 (29.9%)

3437 (26.1%)

 

Maternal substance use in pregnancy

     

 < 0.001

 N-Miss

34

0

1

1403

1438

 

 Denies

8365 (95.9%)

914 (94.9%)

3366 (90.7%)

377 (99.7%)

13,022 (94.5%)

 

 Other

355 (4.1%)

49 (5.1%)

346 (9.3%)

1 (0.3%)

751 (5.5%)

 

Neighbourhood quality, ascending quality

     

 < 0.001

 N-Miss

624

57

366

1170

2217

 

 4

387 (4.8%)

53 (5.8%)

250 (7.5%)

59 (9.7%)

749 (5.8%)

 

 5

331 (4.1%)

58 (6.4%)

251 (7.5%)

41 (6.7%)

681 (5.2%)

 

 6

617 (7.6%)

85 (9.4%)

359 (10.7%)

59 (9.7%)

1120 (8.6%)

 

 7

849 (10.4%)

83 (9.2%)

438 (13.1%)

64 (10.5%)

1434 (11.0%)

 

 8

1102 (13.6%)

113 (12.5%)

461 (13.8%)

92 (15.1%)

1768 (13.6%)

 

 9

1670 (20.5%)

200 (22.1%)

589 (17.6%)

90 (14.7%)

2549 (19.6%)

 

 10

1993 (24.5%)

185 (20.4%)

498 (14.9%)

104 (17.0%)

2780 (21.4%)

 

 11

872 (10.7%)

87 (9.6%)

247 (7.4%)

55 (9.0%)

1261 (9.7%)

 

 Other

309 (3.8%)

42 (4.6%)

254 (7.6%)

47 (7.7%)

652 (5.0%)

 

Maternal social status

     

 < 0.001

 N-Miss

1822

243

1380

1651

5096

 

 2

2330 (33.6%)

203 (28.2%)

611 (26.2%)

36 (27.7%)

3180 (31.4%)

 

 3

3009 (43.4%)

318 (44.2%)

947 (40.6%)

52 (40.0%)

4326 (42.8%)

 

 Other

1593 (23.0%)

199 (27.6%)

775 (33.2%)

42 (32.3%)

2609 (25.8%)

 

Paternal social status

     

 < 0.001

 N-Miss

1218

184

1136

1634

4172

 

 1

1053 (14.0%)

44 (5.6%)

100 (3.9%)

8 (5.4%)

1205 (10.9%)

 

 2

2790 (37.0%)

253 (32.5%)

662 (25.7%)

44 (29.9%)

3749 (34.0%)

 

 3

858 (11.4%)

101 (13.0%)

230 (8.9%)

10 (6.8%)

1199 (10.9%)

 

 4

2047 (27.2%)

268 (34.4%)

1089 (42.3%)

60 (40.8%)

3464 (31.4%)

 

 5

620 (8.2%)

86 (11.0%)

354 (13.7%)

18 (12.2%)

1078 (9.8%)

 

 Other

168 (2.2%)

27 (3.5%)

142 (5.5%)

7 (4.8%)

344 (3.1%)

 
  1. Columns 1–5 represent maternal smoking categories. Reported p-value: Continuous variables—ANOVA, categorical—chi-squared. “Miss”—missing data. Social status was derived from reported occupation according to the UK Registrar General’s classification. From 1 to 3, the occupations refer to manual unskilled, semi-skilled manual, and skilled occupations; 4 refers to skilled non-manual occupations; 5 refers to managerial and technical occupations; 6 refers to professional occupations; and 65 refers to armed forces. Education—“Degree” refers to having a university degree at the time of index pregnancy
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