RESUMO
INTRODUCTION AND HYPOTHESIS: The objective of this trial was to evaluate whether avoidance of episiotomy can decrease the risk of advanced perineal tears. METHODS: In this randomized (1:1) parallel-group superiority trial, primiparous women underwent randomization into "avoidance of episiotomy" (the study group in which episiotomy was allowed only in cases of fetal distress) or "standard care." The primary outcome was the incidence of advanced (3rd- and 4th-degree) perineal tears. RESULTS: The participants were randomized into "standard care" (n = 337) vs. "no episiotomy" (n = 339) groups, not differing in any demographic or obstetric characteristics. Episiotomy rates were significantly lower in the study group (19.6%) compared with the standard care group (29.8%, p = 0.004). Five (1.5%) advanced tears were diagnosed in the study group vs. ten = 3.0% in the controls, yielding an odds ratio of 0.50 (95% CI 0.17-1.50) in favor of the "no episiotomy" group (p = 0.296). No differences were noted in any secondary outcomes. By per protocol analysis (omitting cases in which episiotomy was performed for indications other than fetal distress in the study group), a trend to decreased risk of advanced tears in the study group was noted (p = 0.0956). By per protocol analyses, no severe tears were noted in the 53 vacuum deliveries in the study group vs. 4/65 (6.2%) tears in the controls (p = 0.126). CONCLUSIONS: Since decreased use of episiotomy was not associated with higher rates of severe tears or any other adverse outcomes, we believe this procedure can be avoided in spontaneous as well as vacuum-assisted deliveries. Trial registration no. NCT02356237.