Exposure to tobacco smoke and infant crying

To examine the association of excessive infant crying with maternal smoking during and after pregnancy, paternal smoking, and smoking by other people in the living environment of the infant.

We collected data on infant crying and smoking in a Dutch national sample of 5845 infants aged 0-3 mo (response 62.8%). We defined excessive crying as crying over 3 h a day on more than 3 d of the preceding week.

The prevalence rate of excessive crying was 4.0% (95% CI 3.5 to 4.5%). Excessive crying occurred more frequently among infants of fathers smoking 15 + cigarettes/d (odds ratio (OR) 1.99, 95% CI 1.38 to 2.86) and of mothers smoking 10 + cigarettes/d during pregnancy (OR 1.86, 95% CI 1.02 to 3.42). Infants whose parents were heavy current smokers or whose mothers had been so during pregnancy had a 69% higher prevalence of excessive crying than infants of non-smoking parents (rates: 6.3% and 3.7%, respectively; odds ratio 1.80; 95% CI 1.26 to 2.57).

Parents stopping smoking may prevent excessive infant crying.