Cotinine in meconium indicates risk for early respiratory tract infections.

1. In order to identify potential risks for lower respiratory tract symptoms during early infancy, the concentration of cotinine was measured in meconium of 91 newborns as a parameter of prenatal exposure to tobacco, and a questionnaire was performed with parents at birth. Infants were followed up for the first year of life by monthly telephone interviews. 2. Lower respiratory tract infections during the first 6 months of life were associated with a high concentration of cotinine in meconium (cotinine higher than median vs lower than median; odds ratio 4.9, 95% confidence interval 1.2 to 20.3), while none of the other variables tested including selfreport of parental, prenatal or postnatal tobacco consumption, parents history of atopy, maternal age, presence of siblings, socio-economic status, duration of gestation, birth weight, gender, and duration of breast feeding were identified as independent risks. The occurrence of a lower respiratory tract infection during the first 6 months of life was predicted correctly in 77% of the infants by a cotinine excretion in meconium exceeding the group median. 3. In conclusion, quantification of cotinine in meconium is preferred to historical parameters as an estimate of the risk for early respiratory tract infections.