Klein M C, Janssen P A, MacWilliam L, Kaczorowski J, Johnson B
Department of Family Medicine, McGill University, Montreal, Quebec, Canada.
Am J Obstet Gynecol. 1997 Feb;176(2):403-10. doi: 10.1016/s0002-9378(97)70506-4.
Our purpose was to evaluate risk factors for severe vaginal-perineal trauma and to ascertain determinants of pelvic floor strength.
Secondary analysis of 459 nulliparous women enrolled in a randomized controlled trial of episiotomy was carried out. In a multivariate analysis we examined the association between (1) sulcus tears, (2) third- or fourth-degree tears, and (3) pelvic floor strength and selected demographic, physiologic, pregnancy-related, and intrapartum factors.
Unemployment and shorter second stage of labor were significant predictors of sulcus tears. Episiotomy, forceps use, and birth weight were important predictors of third- and fourth-degree tears. Whereas perineal intactness (use of episiotomy and spontaneous tears) was not influenced by exercise, 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. A total of 35% of the variability in postpartum pelvic floor strength was explained by antepartum strength; however, we were only able to identify 5% of the factors contributing to antepartum pelvic floor strength.
Determinants of sulcus tears appear to be present before pregnancy; third- and fourth-degree tears are related to physician management. Exercise mitigates the potential for severe trauma induced by episiotomy.
我们的目的是评估严重阴道会阴创伤的危险因素，并确定盆底肌力的决定因素。
对纳入会阴切开术随机对照试验的459名未生育女性进行二次分析。在多变量分析中，我们研究了以下因素之间的关联：（1）沟状撕裂，（2）三度或四度撕裂，以及（3）盆底肌力与选定的人口统计学、生理学、妊娠相关和产时因素。
失业和第二产程较短是沟状撕裂的重要预测因素。会阴切开术、产钳使用和出生体重是三度和四度撕裂的重要预测因素。虽然会阴完整性（会阴切开术和自然撕裂的情况）不受运动影响，但在进行会阴切开术时，较强的运动状况与较少的三度和四度撕裂相关。运动不影响沟状撕裂的发生率。产后盆底肌力变异性的35%可由产前肌力解释；然而，我们仅能确定导致产前盆底肌力的5%的因素。
沟状撕裂的决定因素似乎在怀孕前就已存在；三度和四度撕裂与医生的处理有关。运动可减轻会阴切开术所致严重创伤的可能性。
