TABLE 1

Distribution of Exposure Characteristics in Relation to Maternal Smoking During Pregnancy Among Children in the BAMSE Birth Cohort (n = 3798)

In Utero Exposure to Maternal Smokinga
No, n = 3314 (87.3%)Yes, n = 483 (12.7%)
n%n%
Gender
 Male167550.524550.7
Breastfeeding
 ≥4 mo264781.332969.1
Socioeconomic statusb
 Low48214.814530.6
 High278185.232969.4
Parental allergic disease
 Yes100130.413027.8
Maternal age at birth
 <26 y2256.86012.4
Parental smoking at 16 yc
 Yes2218.318951.9
Asthma at 16 y
 Yes1726.3277.1
Rhinitis at 16 y
 Yes69725.78722.9
Eczema at 16 y
 Yes2569.34812.5
  • a The mother smoked ≥1 cigarette per day at any time during pregnancy.

  • b Children were categorized on the bases of the parents’ occupations. Manual workers were classified as having low socioeconomic status and nonmanual workers as having high socioeconomic status. Detailed definitions can be found in the online supplement.

  • c Any parent smoked ≥1 cigarette per day.