Table 4 Characteristics of pregnancy and pregnancy outcomes by environmental tobacco smoke (ETS). Odds ratio (OR) for ETS and 95% confidence intervals (CI) unadjusted and adjusted for age, active smoking, education and parity. p-values from General Linear Model

Gestational age at delivery (weeks)

preterm (< 34)

23 (1.7%)

8 (3.5%)

2.15 (0.94–4.91)

2.26 (0.98–5.22)

late preterm (34- < 37)

74 (5.4%)

16 (6.9%)

1.34 (0.76–2.37)

1.37 (0.76–2.45)

early term (37- < 39)

299 (21.8%)

43 (18.6%)

0.89 (0.61–1.29)

0.90 (0.61–1.31)

full term (39- < 41)

810 (59.0%)

131 (56.7%)

1^#

1^#

late term (41+)

166 (12.1%)

33 (14.3%)

1.23 (0.81–1.86)

1.19 (0.77–1.84)

Method of delivery

Vaginal delivery

901 (65.7%)

148 (64.1%)

1^#

1^#

Cesarean

471 (34.3%)

83 (35.9%)

1.07 (0.80–1.44)

1.23 (0.90–1.66)

Apgar 1 min

7–10

1337 (97.4%)

217 (93.9%)

1^#

1^#

< 7

35 (2.6%)

14 (6.1%)

2.46 (1.30–4.66)

2.68 (1.40–5.11)

Apgar 5 min

7–10

1363 (99.3%)

226 (97.8%)

1^#

1^#

< 7

9 (0.7%)

5 (2.2%)

3.35 (1.11–10.09)

3.55 (1.16–10.88)

Birth weight (g)

mean ± SD

3156 ± 458

3110 ± 504

1.28 (0.79–2.08)

1.23 (0.91–1.66)

Admittance of newborn

yes

89 (6.5%)

25 (10.8%)

1.75 (1.10–2.79)

1.87 (1.16–3.01)

Anomaly

yes

6 (0.4%)

2 (0.9%)

1.99 (0.40–9.91)

1.26 (0.21–7.67)