Table 1 SGA-births in percent (95% CI) among mothers with known and unknown smoking status. N = 904,982.

All

436,114

7.4 (7.4–7.5)

8.6 (8.4–8.8)

468,868

8.4 (8.3–8.5)

9.8 (9.5–10.0)

  < =19 years

10,487

10.6 (10.0–11.3)

12.9 (11.1–14.8)

9459

11.8 (11.1–12.5)

13.2 (11.3–15.3)

 20–29 years

211,688

7.8 (7.7–7.9)

9.1 (8.8–9.5)

215,520

9.0 (8.9–9.1)

10.8 (10.4–11.2)

 30–39 years

204,217

6.8 (6.7–6.9)

7.9 (7.6–8.2)

229,046

7.6 (7.5–7.7)

8.9 (8.6–9.2)

  > =40 years

9722

8.6 (8.0–9.3)

8.7 (7.4–10.3)

14,843

9.7 (9.2–10.2)

9.8 (8.7–11.0)

 Married, living together, etc.

402,035

7.2 (7.1–7.3)

8.3 (8.1–8.5)

432,971

8.1 (8.1–8.2)

9.5 (9.3–9.8)

 Divorced, living alone, etc.

34,079

10.4 (10.1–10.8)

12.5 (11.6–13.5)

35,897

11.7 (11.3–12.0)

12.4 (11.5–13.3)

 No previous child

177,317

10.1 (10.0–10.3)

11.5 (11.1–11.9)

198,568

11.7 (11.5–11.8)

12.7 (12.4–13.1)

 One previous child

155,543

5.6 (5.5–5.8)

6.4 (6.0–6.7)

168,674

6.1 (6.0–6.2)

7.2 (6.9–7.5)

 Two + pr. Children

103,254

5.5 (5.4–5.7)

6.7 (6.3–7.1)

101,626

5.9 (5.8–6.1)

7.8 (7.3–8.2)

 Norway/ Nordic countries

383,385

6.9 (6.8–7.0)

7.7 (7.4–7.9)

375,348

7.7 (7.6–7.8)

8.4 (8.2–8.7)

 Europe outside the Nordic region

16,013

8.5 (8.0–9.0)

8.9 (7.9–10.0)

37,296

9.0 (8.7–9.3)

9.6 (8.9–10.3)

 Asia

23,864

14.2 (13.7–14.7)

15.0 (14.0–16.0)

32,864

13.2 (12.8–13.7)

15.3 (14.5–16.1)

 Africa

9321

13.7 (12.9–14.6)

13.9 (12.6–15.3)

17,848

14.7 (14.1–15.3)

15.5 (14.4–16.5)

 Others ^a

3531

8.0 (7.0–9.1)

9.5 (7.3–12.1)

5512

9.9 (9.1–10.8)

10.5 (8.7–12.5)

 University etc.

177,919

6.1 (6.0–6.2)

7.0 (6.7–7.3)

230,175

7.4 (7.3–7.5)

8.5 (8.2–8.8)

 Medium

156,437

7.1 (7.0–7.2)

8.2 (7.8–8.6)

125,663

8.0 (7.8–8.2)

9.2 (8.8–9.7)

 Primary

82,492

9.8 (9.6–10.1)

10.9 (10.3–11.4)

83,018

10.7 (10.5–10.9)

12.0 (11.4–12.6)