. 2010 Oct 22;22(6):1809–1819. doi: 10.1007/s00198-010-1415-y

Table 2.

Sex-specific associations of maternal and paternal smoking with total body less head bone outcomes at age 9.9 years in multiple imputation analysis (boys N = 3,530; girls N = 3,591)

		Mean difference	95% CI	P value	Mean difference	95% CI	P value	Mean difference	95% CI	P value
Boys		TBLH BMC (SD score: 1 SD = 174.6 g)			TBLH BA (SD score: 1 SD = 154.9 cm²)			TBLH BMD (SD score: 1 SD = 0.053 g/cm²)
Maternal smoking in any trimester
Model 1		0.01	−0.07–0.09	0.767	0.00	−0.08–0.08	0.992	0.04	−0.05–0.12	0.419
Model 2		0.05	−0.03–0.14	0.186	0.05	−0.03–0.13	0.232	0.06	−0.03–0.15	0.177
Model 3		0.00	−0.05–0.04	0.885	−0.01	−0.04–0.03	0.736	0.01	−0.06–0.08	0.752
Maternal smoking in all trimesters
Model 1		0.07	−0.04–0.17	0.200	0.05	−0.05–0.15	0.356	0.10	−0.01–0.21	0.086
Model 2		0.13	0.02–0.23	0.016	0.12	0.01–0.22	0.025	0.13	0.02–0.24	0.020
Model 3		0.00	−0.06–0.05	0.877	−0.02	−0.06–0.03	0.482	0.03	−0.06–0.12	0.523
Paternal smoking
Model 1		0.02	−0.05–0.10	0.519	0.03	−0.04–0.10	0.405	0.01	−0.07–0.08	0.887
Model 2		0.03	−0.04–0.10	0.425	0.04	−0.03–0.11	0.305	0.01	−0.07–0.08	0.833
Model 3		−0.02	−0.05–0.02	0.357	−0.01	−0.04–0.02	0.581	−0.03	−0.09–0.03	0.313
Combined models
Model 1	Maternal smoking^a	0.01	−0.08–0.09	0.830	−0.01	−0.09–0.08	0.888	0.04	−0.05–0.13	0.396
Model 1	Paternal smoking	0.03	−0.04–0.10	0.465	0.04	−0.03–0.11	0.298	0.00	−0.08–0.08	0.985
Model 2	Maternal smoking^a	0.05	−0.04–0.13	0.277	0.04	−0.04–0.12	0.369	0.06	−0.03–0.16	0.194
Model 2	Paternal smoking	0.02	−0.05–0.09	0.588	0.03	−0.04–0.10	0.409	−0.01	−0.08–0.07	0.894
Model 3	Maternal smoking^a	0.00	−0.04–0.05	0.925	0.00	−0.04–0.03	0.845	0.02	−0.05–0.10	0.523
Model 3	Paternal smoking	−0.02	−0.06–0.02	0.383	−0.01	−0.04–0.02	0.644	−0.03	−0.10–0.03	0.266
Girls		TBLH BMC (SD score: 1 SD = 191.5 g)			TBLH BA (SD score: 1 SD = 172.3 cm²)			TBLH BMD (SD score: 1 SD = 0.055 g/cm²)
Maternal smoking in any trimester
Model 1		0.13	0.05–0.22	0.003	0.13	0.04–0.21	0.004	0.13	0.04–0.22	0.005
Model 2		0.17	0.08–0.25	<0.001	0.17	0.08–0.25	<0.001	0.15	0.06–0.24	0.001
Model 3		0.02	−0.02–0.06	0.384	0.02	−0.01–0.06	0.205	0.02	−0.04–0.08	0.528
Maternal smoking in all trimesters
Model 1		0.15	0.03–0.26	0.011	0.15	0.04–0.26	0.009	0.13	0.01–0.24	0.037
Model 2		0.20	0.09–0.32	0.001	0.21	0.10–0.32	<0.001	0.16	0.04–0.28	0.008
Model 3		0.02	−0.03–0.07	0.371	0.03	−0.01–0.08	0.127	0.01	−0.07–0.09	0.871
Paternal smoking
Model 1		0.15	0.08–0.22	<0.001	0.14	0.08–0.21	<0.001	0.14	0.07–0.21	<0.001
Model 2		0.16	0.09–0.23	<0.001	0.15	0.09–0.22	<0.001	0.15	0.07–0.22	<0.001
Model 3		0.03	−0.00–0.07	0.058	0.03	0.00–0.06	0.029	0.04	−0.02–0.09	0.164
Combined models
Model 1	Maternal smoking^a	0.10	0.01–0.19	0.025	0.10	0.01–0.19	0.030	0.10	0.01–0.19	0.032
Model 1	Paternal smoking	0.12	0.05–0.20	0.001	0.12	0.05–0.19	0.002	0.12	0.04–0.19	0.004
Model 2	Maternal smoking^a	0.13	0.04–0.22	0.004	0.13	0.04–0.22	0.003	0.12	0.03–0.21	0.011
Model 2	Paternal smoking	0.12	0.05–0.19	0.001	0.12	0.05–0.19	0.001	0.11	0.04–0.19	0.004
Model 3	Maternal smoking^a	0.01	−0.03–0.05	0.670	0.01	−0.02–0.05	0.457	0.01	−0.05–0.08	0.706
Model 3	Paternal smoking	0.03	−0.01–0.06	0.101	0.03	−0.00–0.06	0.087	0.04	−0.02–0.10	0.198

Model 1 is adjusted for the child’s age, mother’s parity, household social class and maternal/paternal factors (age, height, pre-pregnancy BMI, education).

Model 2 is adjusted additionally for the child’s gestational age and birth weight

Model 3 is adjusted for all these plus the child’s height and weight at age 9.9 years

Reference category for maternal smoking variables is “Never smoked during pregnancy” and for paternal smoking variable is “Non-smoking”

BA bone area, BMC bone mineral content, BMD bone mineral density, TBLH total body less head

^aMaternal smoking in any trimester