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

Table 4 Parental smoking during pregnancy correlated with birth weight (g) and low birth weight, stratified by residence

	Urban				Rural
	Linear regression		Logistic regression		Linear regression		Logistic regression
	Birthweight	p	Low birthweight	p	Birthweight	p	Low birthweight	p
	Mean ± SE	p	OR (95% CI)	p	Mean ± SE	p	OR (95% CI)	p
Parental smoking during pregnancy^a
Neither parent	3062 ± 26.3	-	1.00	-	3057 ± 19.8	-	1.00	-
Only father	3122 ± 16.4	0.053	0.58 (0.27-1.26)	0.168	3073 ± 10.3	0.489	1.48 (0.67-3.28)	0.332
Only mother	3048 ± 86.3	0.878	0.78 (0.08-8.12)	0.834	2795 ± 63.2	<0.001	5.91 (0.98-35.67)	0.053
Both parents	2876 ± 90.6	0.049	0.93 (0.11-7.90)	0.947	3029 ± 51.9	0.608	8.77 (0.94-81.47)	0.056
Paternal smoking amount^b
None	3081 ± 25.2	-	1.00	-	3018 ± 20.9	-	1.00	-
1-10 cigarettes/day	3151 ± 23.4	0.044	0.78 (0.46-1.33)	0.361	3074 ± 17.4	0.041	0.79 (0.50-1.23)	0.296
11-20 cigarettes/day	3103 ± 26.1	0.551	0.94 (0.55-1.60)	0.809	3090 ± 16.0	0.006	0.49 (0.30-0.78)	0.003
>20 cigarettes/day	2850 ± 47.4	<0.001	2.89 (1.59-5.27)	0.001	2940 ± 35.4	0.058	1.52 (0.85-2.71)	0.160
Maternal smoking amount^b
None	3105 ± 14.7	-	1.00	-	3069 ± 10.3	-	1.00	-
1-10 cigarettes/day	2913 ± 86.8	0.029	1.41 (0.49-4.10)	0.524	3012 ± 61.2	0.359	1.94 (0.80-4.69)	0.143
>10 cigarettes/day	2806 ± 154.9	0.055	1.13 (0.14-9.01)	0.905	2704 ± 82.1	<0.001	6.23 (2.60-14.92)	<0.001
Smoking amount in both parents^b
None	3078 ± 26.4	-	1.00	-	3053 ± 21.9	-	1.00	-
1-20 cigarettes/day	3127 ± 17.3	0.117	0.87 (0.55-1.40)	0.577	3073 ± 11.9	0.431	0.98 (0.62-1.53)	0.911
>20 cigarettes/day	2855 ± 44.5	<0.001	2.66 (1.46-4.84)	0.001	2954 ± 31.9	0.010	1.90 (1.04-3.46)	0.036

Note. SE = standard error; OR = odds ratio; CI = confidence interval.
^aAdjusted for birth order, maternal age at delivery, maternal employment status, and parental BMI.
^bAdjusted for birth order.

ISSN: 1471-2393