Table 3

Number of children and age at first birth according to smoking status, women

Model 1Model 2Model 3Model 4
Number of children
Smoking status
 Never (n=1681)1.57±1.16*1.56±0.03*1.53±0.021.53±0.02
 Former (n=972)1.45±1.07†1.47±0.04*†1.48±0.031.48±0.03
 Current (n=877)1.38±1.05†1.41±0.04†1.45±0.031.46±0.03
p Value3.79×1050.0090.1180.171
HSI categories
 Low (n=233)1.42±1.001.46±0.071.45±0.061.45±0.06
 Medium (n=312)1.39±1.011.37±0.061.38±0.051.38±0.05
 High (n=59)1.46±1.221.44±0.141.42±0.131.42±0.13
p Value0.8530.6250.7330.714
Age at first birth
Smoking status
 Never (n=1294)26.9±5.227.0±0.1*†27.0±0.1*†27.0±0.1*†
 Former (n=728)27.4±5.427.2±0.2†27.3±0.2†27.2±0.2*
 Current (n=640)26.7±5.226.6±0.2*26.6±0.2*26.6±0.2†
p Value0.0160.0350.0510.047
HSI categories
 Low (n=178)27.4±5.1*27.1±0.4*27.0±0.4*27.0±0.4*
 Medium (n=236)26.7±5.3*†26.8±0.3*26.9±0.3*26.9±0.3*
 High (n=41)24.6±4.6†24.4±0.8†24.5±0.8†24.5±0.8†
p Value0.0090.0140.0200.016
  • Results are expressed as mean±SD or as adjusted mean±SE. Between group comparisons by analysis of variance. Model 1, unadjusted; model 2, adjusted for age, body mass index, Caucasian status (yes/no), alcohol consumption (four groups), caffeinated drinks consumption (four groups), educational level (three groups) and receiving social help (yes/no); model 3, same as model 2 plus diabetes (yes/no), current contraception (yes/no), marital status, retinoic acid and anticancer drugs; model 4, same as 3 plus ever used contraception (yes/no). Post-hoc bivariate analyses by the Scheffe's method; Groups with different superscript signs ‘* and †’ are significantly different at p<0.05.

  • HSI, Heaviness of Smoking Index.