Table 2 Absolute numbers of cigarettes smoked per day during pregnancy in Murmansk County, Northwest Russia, in relation to socio-demographic characteristics of women (N = 4,774)

Maternal age (years)

0.017^c

  ≤ 19

698

7

5–10

 20–24

1,767

7

5–10

 25–29

1,271

7

5–10

 30–34

743

7

5–10

  ≥ 35

295

10

5–10

Residence

0.248^d

 Urban

3,685

7

5–10

 Rural

1,089

7

5–10

Ethnicity

0.433^d

 Russian

4,642

7

5–10

 Other

132

7

5–10

Education

<0.001^c

 Incomplete secondary

497

8

5–10

 Secondary

2,545

8

5–10

 Vocational

1,369

7

5–10

 University

354

5

5–10

 Unknown

9

10

5–10

Marital status

<0.001^c

 Married

2,562

6

5–10

 Cohabitation

1,406

10

5–10

 Single

806

10

5–10

Parity

<0.001^c

 0

2,525

7

5–10

 1

1,667

7

5–10

  ≥ 2

582

10

5–10

Alcohol abuse

 No

4,671

7

5–10

<0.001^d

 Yes

103

10

10–20