Aim: 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.
Methods: 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.
Results: 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).
Conclusion: Parents stopping smoking may prevent excessive infant crying.