No episiotomy versus selective lateral/mediolateral episiotomy (EPITRIAL): an interim analysis.

No difference in the rates of advanced perineal tears was found between groups; however, the main limitation of our study was unexpectedly high rates of episiotomy in the nonepisiotomy group. Thus, the main conclusion is that investigator monitoring and education should be continuously practiced throughout the trial duration, stressing the importance of adherence to the protocol.