Adverse effects of parental smoking during pregnancy in urban and rural areas

Table 3 Parental smoking during pregnancy correlated with gestational age (weeks) and preterm birth

	Gestational age	p	Preterm birth	p
	Mean ± SE	p	OR (95% CI)	p
Parental smoking during pregnancy^a
Neither parent	39.79 ± 0.1	-	1.00	-
Only father	39.75 ± 0.1	0.595	1.16 (0.78-1.71)	0.470
Only mother	38.83 ± 0.2	<0.001	3.37 (1.58-7.19)	0.002
Both parents	39.21 ± 0.2	0.006	3.10 (1.37-7.04)	0.007
Paternal smoking amount^b
None	39.64 ± 0.1	-	1.00	-
1-10 cigarettes/day	39.93 ± 0.1	<0.001	0.51 (0.34-0.75)	0.001
11-20 cigarettes/day	39.76 ± 0.1	0.144	0.78 (0.55-1.11)	0.163
>20 cigarettes/day	39.20 ± 0.1	0.001	2.11 (1.38-3.23)	0.001
Maternal smoking amount^b
None	39.78 ± 0.1	-	1.00	-
1-10 cigarettes/day	39.06 ± 0.2	<0.001	2.68 (1.45-4.95)	0.002
>10 cigarettes/day	38.77 ± 0.3	<0.001	5.54 (2.61-11.76)	<0.001
Smoking amount in both parents^b
None	39.73 ± 0.1	-	1.00	-
1-20 cigarettes/day	39.82 ± 0.1	0.231	0.86 (0.61-1.20)	0.373
>20 cigarettes/day	39.26 ± 0.1	<0.001	2.30 (1.49-3.56)	<0.001

Note. SE = standard error; OR = odds ratio; CI = confidence interval.
^aAdjusted for birth order, maternal age at delivery, father’s education, household income, and residence.
^bAdjusted for birth order.

ISSN: 1471-2393