The Authors have examined the results of 14.703 colposcopic examinations performed at the Social Medicine Center of the Province of Florence between 1974 and 1978, grouping the women according to childbearing and age. The purpose was to verify if mechanical and traumatic factors related to delivery may be responsible for modifications of the epithelial lining of the uterine cervix and especially for ectopy. The Authors have shown that the percentage of incidence of colposcopic picture of portio with original squamous epithelium and ectopy maintain almost identical values in nulliparae and pluriparae. Delivery does not significantly influence the presence of ectopy: the slight increase of such a picture in pluriparae is attributed to the formation of "ektropion", and the Authors define this picture, clearly separating it from the ectopy picture. The presence of ectopy decreases considerably as the women's age increases: this is attributed to therapeutic treatments possibly undergone over the years and to the spontaneous mending processes which are completed with age. Ectopy and its typical transformation zones are found in high percentages in the age group of women under 20. This corresponds exactly to the percentages reported by a few Authors on the presence of jodonegative zones in newborns. On the basis of these results, the Authors conclude that delivery does not modify the condition of the uterine cervix and deny any relation between traumatic factors and "cervical erosion".