Asistencia obstétrica y trauma perineal

Abstract

Objectives In our center, the overall frequency of episiotomy has markedly decreased while the frequency of midline episiotomy has increased. The aims of the present study were two-fold: a) to determine whether restrictive episiotomy is associated with a lower frequency of perineal injury, and b) to identify perineal injury due to the predominant use of midline episiotomy. Material and method A total of 90,030 vaginal deliveries in the Hospital Universitario Materno Infantil de Canarias from January 1, 1992 to December 31, 2005 were studied. The frequency and type of episiotomy, the frequency of tears and their severity, and the association between type of episiotomy and the frequency and severity of perineal tears were analyzed. In addition, the same variables were studied in forceps deliveries. The chi-squared test was used and statistical significance was set at a probability value of less than 5%. When statistically significant differences were detected, odds ratios with 95% confidence intervals were calculated. The SPSS V.11 statistical package was used. Results The frequency of episiotomy decreased from 73.3% in 1992 to 38.2% in 2005. The frequency of mediolateral episiotomy decreased from 59.3% in 1992 to 18.2% in 2005 while that of midline episiotomy increased from 14% to 20%. The number of grade I and II tears increased while no significant changes in the frequency of grade III and IV tears were observed. The frequency of grade I and II tears was significantly higher when episiotomy was not performed. No statistically significant differences were found in the frequency of grade I and II tears between midline and mediolateral episiotomy or in the frequency of grade III and IV tears between these two procedures. In forceps deliveries, the frequency of tears, both grades I and II (49.5%) and grades III and IV (8.4%), was higher when episiotomy was not performed and significant differences were found in comparison with the frequency of tears in women with midline episiotomy (8.4% grade I or II tears and 4.2% grades III or IV) or mediolateral episiotomy (10.2% grade I or II tears and 4% grades III or IV tears). No differences were found in the frequency of grade III and IV tears between midline and mediolateral episiotomy. Conclusions a) A restrictive episiotomy policy should be followed in vaginal deliveries; b) midline episiotomy should be performed whenever, in the obstetrician’s opinion, the course of labor and expulsion and the perineal characteristics allow this procedure, since it does not increase the frequency of grade III-IV tears, and c) episiotomy should be performed more frequently in forceps deliveries, with a preference for midline episiotomy since, if correctly indicated, this procedure does not increase the frequency of grade III-IV tears.