In this retrospective study, the role of Gravidic Maternal Ponderal Increase (GMPI) within pathogenetic factors of perineal obstetric injuries, is analysed. TO this purpose, clinical data of 58 puerperae, who underwent a functional evaluation of perineum 30 days after delivery, were examined. The results of this study seem to indicate an autonomous pathogenetic role of GMPI, besides the indirect relation deriving from the association with other risk factors (age, parity, diabetes, fetal megalosomia, ecc).