The Effect of Smoking on Lactation and Infantile Colic

To the Editor.— The deleterious effect of smoking on pregnancy and infant morbidity is now well recognized. Less is known about the effect of maternal smoking on lactation and the breast-fed infant. Because smoking is reported to shorten the period of breast-feeding,1our aim was to investigate whether this was related to sociodemographic factors. Study.— Data were collected about maternal smoking, breast-feeding, infant disorders, and demographic characteristics in a random sample of 16% of the women giving birth in Oslo, Norway, in 1985 (N = 885). They answered a mailed questionnaire (78% response rate) four months post partum. The infant birth weights in this study did not differ from those of official birth statistics. Validity testing was done by subsequent interviews with 96 of the respondents. Statistical analysis used the χ2test. Three hundred forty-eight of the mothers (39.6%) were daily smokers (≥1 cigarette per day) and 18 (2%)