[Prevention of obstetrical damage to the perineum. Proposal for a fetal-pelvic index for the selection of parturients at risk].

BACKGROUND

According to some authors, vaginal delivery always causes denervation of perineum and the greater the damage the longer the second labour phase (the so-called "delivering phase"). Therefore, it is necessary to reduce the number of too prolonged labours, but it is equally important to avoid an uncontrolled increase of cesarean sections. In order to achieve this objective, it is important to carry out a careful selection among laboring women and choose those most at risk for whom cesarean section is strongly recommended. On the basis of the data collected by the medical literature and in consideration of the pathogenetic role of the outlet dystocia, we have tried to identify a simple and effective prognostic index resulting from the different pelvimetric and ultrasonographic parameters.

METHODS

In 72 full-term pregnant women, we have taken into account the ultrasonographic parameters expressing the fetal dimension (cephalic diameters, cephalic and abdominal circumferences, estimated fetal weight according to Haddlok), the outlet pelvic diameters (trans-ischial and coccygeal-pubic) and a fetal-pelvic index derived from these parameters.

RESULTS

If taken individually, these parameters do not seem to have any direct connection with the length of the delivering phase, but the combination of the cephalic and external pelvimetric diameters has produced a significative statistical coefficient.

CONCLUSIONS

On the basis of the data collected, it is suggested that a careful evaluation of external pelvimetric and cephalic parameters would be useful from the clinical point of view.