Table 1 Socio-demographic characteristics of pregnant women (N = 12,871) in Murmansk County, Northwest Russia, in relation to their smoking status during pregnancy

Maternal age (years)

<0.001

  ≤ 19

1,513

12.8

8.8

 20–24

4,491

35.1

34.5

 25–29

3,788

28.6

31.9

 30–34

2,144

16.3

17.7

  ≥ 35

935

7.3

7.1

Residence

<0.001

 Urban

10,565

80.6

86.6

 Rural

2,306

19.4

13.4

Ethnicity

0.570

 Russian

12,521

97.2

97.4

 Other

350

2.8

2.6

Education

<0.001

 Incomplete secondary

988

9.3

2.9

 Secondary

5,649

47.2

33.9

 Vocational

4,071

30.5

34.9

 University

2,099

12.3

28.2

 Unknown

64

0.7

0.1

Marital status

<0.001

 Married

7,503

53.7

72.1

 Cohabitation

3,239

27.8

17.2

 Single

2,129

18.5

10.7

Parity

<0.001

 0

7,380

55.6

62.4

 1

4,252

33.3

32.4

  ≥ 2

1,239

11.1

5.2

Alcohol abuse

<0.001

 No

12,654

97.8

100.0

 Yes

217

2.2

0.0