Factors Influencing Perineal Trauma during Delivery

Objectives: our purpose was to evaluate risk factors for severe vaginal-perineal trauma and to ascertain determinants of pelvic floor strength.Study Design: a secondary analysis of 459 nulliparous women enrolled in a randomized controlled trial of episiotomy. In a multivariate analysis we examined the association between (1) sulcus tears, (2) third or fourth degree tears, and selected demographic, physiologic, pregnancy-related and intrapartum factors, including the role of exercise.Results: unemployment and shorter second stage of labour were significant predictors of sulcus tears. Episiotomy, forceps use and birth weight were important predictors of third and fourth degree tears. A strong exercise profile was associated with fewer third and fourth degree tears in the presence of episiotomy. Exercise did not influence the rate of sulcus tears. Exercise was not associated with the use of episiotomy.Conclusions: contrary to currently held beliefs, third and fourth degree tears are related to physician management, but the determinants of sulcus tears appear to be present before pregnancy. Exercise does not increase the need for episiotomy but does reduce the risk for associated third and fourth degree tears.