In a semilongitudinal intervention study women in maternity homes were con- tacted by instructed fifth year students of the Medical Faculty Masaryk University within the framework of individual counselling focused on promotion of breastfe- eding , improvement of dietary habits and non-smoking. While intervention to promote breastfeeding is implemened in all women, counselling as regards smo- king and nutrition is used only in some of the women, the rest form the control group. The results of consultations are checked after 3 and 6 months after delivery by means of questionnaires. The published results comprise data from 236 women from four maternity homes. During pregnancy the majority of women do not smoke (cca 92%): 59% of these women never smoked, 33% stopped smoking (usually spontaneously)before beco- ming pregnant or after pregnancy was diagnosed. Women under 20 years with a lower education smoke more frequently.Smoking of mothers during pregnancy influenced intrauterine foetal development in a significant way: the mean birth weight of neonates of smoking mothers was by 114 g lower than in neonates born to non-smokers and by 139 lower as compared with the birth weight of neonates of ex-smokers. Asphyxia of neonates of smoking mothers was ten times more frequent than in infants of non-smokers. The delivery was twice as often abnormal in smokers. Smokers breastfed their infants for less than threemonths after delivery. Ex-smo- kers stop breastfeeding their infants during the first six months more frequently than women who never smoked (59.2% vs.43%). The quit smoking intervention had the effect that more women who stopped smoking during pregnancy avoided smoking also during six months after delivery. It is thus obvious that intervention by a professional in the maternity home has a positive effect. Quit smoking counselling must be included in the routine work of physicians in prenatal clinics, in maternity homes and in paediatric practice.

        Key words: smoking - pregnancy - breastfeeding - child health