[Teenage and adult pregnancy: different correlations between socio-economic status and smoking].

Introduction: Smoking occurs frequently during pregnancy, thereby putting mother and child at health risks. Low socio-economic status is a risk factor for smoking.
Aim: To investigate the relationship between smoking and low income in teenage and adult pregnancy, which is an important measure of poor socioeconomic status.
Method: The authors used subject-level data from the US NSDUH database, which contains information on pregnancies and smoking.
Results: Teenage pregnancy is associated with higher, whereas adult pregnancy with lower prevalence of smoking, compared to the age-matched female population. The association between income and smoking is age-dependent. Among adults there is an inverse relationship (high income -- low-risk of smoking), while in teenage pregnancy smoking increases with income.
Conclusions: To investigate in teenage and adult pregnancy the relationship between smoking and low income, which is an important measure of poor socio-economic status. Higher socioeconomic status may be associated with risky behaviour, thereby increasing both the risk of smoking and early pregnancy.