Background: It is well known that vaginal birth, even under apparently normal circumstances, involves a significant mechanical straining of the various muscular connective structures which make up the pelvic floor and that an unusual strain of the perineal plates can cause morphologic-functional alterations which are not entirely reversible. The integrity of structures which make up the "pelvic floor" and the "endopelvic fascia" is the fundamental element to maintaining a normal anatomic position of the pelvic organs in the various functional conditions. Consequently prolapse of female pelvic organs can be linked back to the functional limitations of perineal plates (muscular support fascia system) and/or of the ligaments of the sub-peritoneal endopelvic connective tissue (ligament suspension system)., Methods: After birth 537 mothers underwent a urological and gynecological examinations as follows: collection of clinical data regarding pregnancy development and birth; medical history regarding the number of day- and night-time urinations, urinary volume, possible encouraging factors and pre-urinary sensations; objective urological and gynecological examination (pubo-coccygeal test, highlighting of possible agonistic and antagonistic muscular synergies, stress test, evaluation and staging of vaginal prolapse according to Baden and Walker; instrumental evaluation in cases of post-partum urinary incontinence. Simple regression analyses were carried out where prolapse of various vaginal segments were proportionately related to the various risk factors., Results: Maternal age at birth, parity, weight before pregnancy and at term, weight increase, duration of second stage of labour, development and characteristics of the birth, perineal condition and neonatal weight were all variables considered risk factors while prolapse in each vaginal segment, PC-test, involuntary reflex execution of opposite command and uterine retroversion were all "response variables" whose dependence on various risk factors was studied. Analysis of the associations between the various pairs of variables showed a correlation, both positive and negative, whether the population considered was that of all mothers or that of primiparae., Conclusions: In the light of the results of this study, it can be said that there are two important pathogenetic factors: the tissue factors and the iatrogenic factor. Elevated maternal age and multiparity underline the role of the tissue factor in the pathogenesis of obstetric perineal damage. With regard to the iatrogenic factor it is interesting to note a higher concentration of symptomatic women cases where labour had been induced or birth had been achieved through instrumental delivery.