Use of hyaluronidase in the prevention of perineal trauma in spontaneous delivery: a randomized clinical trial placebo-controlled double-blind

Hyaluronidase (Haas) is a complex enzyme that acts on the connective tissue. There are several studies on the implementation of Haas in the perineal area in order to reduce the incidence of episiotomy and spontaneous lacerations Despite positive results, methodological limitations of these studies justify the controversy about the benefits of its use in spontaneous delivery. The aim of this study was to compare the frequency of trauma and the degree of perineal lacerations in vaginal deliveries, with and without the use of injectable Haase in the posterior region of the perineum. This is a randomized clinical trial, placebo-controlled, double-blind study, conducted in 2008 in the Amparo Maternal Birth Center located in São Paulo city. The sample of 156 pregnant women were randomly allocated to experimental groups (n = 76) and control (n = 80). We included only women with singleton pregnancies, pregnancy to term without previous vaginal deliveries and who had spontaneous delivery in semi-sitting position without anesthesia by intra or extra-dural. In the second stage of labor, women in the experimental group received injections of Haas in the posterior perineal area and those of the control group received injections of placebo. The vials of solution were previously masked and identified by code number. The assessment of perineal outcome was also performed under masked by a nurse-judge. For the inferential analysis of data, we performed the Fisher exact test, sotailed and were considered statistically significant p values.