Table 1 Characteristics of pregnant women by environmental tobacco smoke (ETS). p-values from Fisher’s exact probability test

Characteristic

Category

No (n = 1372)

Yes (n = 231)

p-value

Age (years)

< 25 y

473 (34.5%)

85 (36.8%)

0.296

25–29 y

424 (30.9%)

72 (31.2%)

30–34 y

268 (19.5%)

46 (19.9%)

35+ y

207 (15.1%)

28 (12.1%)

Active smoking

yes

8 (0.6%)

15 (6.5%)

< 0.001

Residence

city

942 (68.7%)

148 (64.1%)

0.171

village

430 (31.3%)

83 (35.9%)

Ethnicity

Farsi

209 (15.2%)

29 (12.6%)

0.551

Turk

1143 (83.3%)

198 (85.7%)

other

20 (1.5%)

4 (1.7%)

Education

Elementary school

279 (20.3%)

67 (29.0%)

< 0.001

High school

795 (57.9%)

141 (61.0%)

College/university

298 (21.7%)

23 (10.0%)

Body weight

underweight (BMI < 18.5)

70 (5.1%)

12 (5.2%)

0.904

normal (BMI 18.5- < 25)

1158 (84.4%)

197 (85.3%)

overweight (BMI > =25)

144 (10.5%)

22 (9.5%)

Parity

1

553 (40.3%)

95 (41.1%)

0.486

2

520 (37.9%)

77 (33.3%)

3

237 (17.3%)

46 (19.9%)

4+

62 (4.5%)

13 (5.6%)

Asthma

yes

26 (1.9%)

8 (3.5%)

0.137