Friedman Alexander M, Ananth Cande V, Prendergast Eri, D'Alton Mary E, Wright Jason D
Divisions of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Obstetrics and Gynecology, College of Physicians and Surgeons, and the Department of Epidemiology, Mailman School of Public Health, Columbia University, and New York Presbyterian Hospital, New York, New York.
Obstet Gynecol. 2015 Apr;125(4):927-937. doi: 10.1097/AOG.0000000000000720.
To examine the patterns and predictors of third-degree and fourth-degree laceration in women undergoing vaginal delivery.
We identified a population-based cohort of women in the United States who underwent a vaginal delivery between 1998 and 2010 using the Nationwide Inpatient Sample. Multivariable log-linear regression models were developed to account for patient, obstetric, and hospital factors related to lacerations. Between-hospital variability of laceration rates was calculated using generalized log-linear mixed models.
Among 7,096,056 women who underwent vaginal delivery in 3,070 hospitals, 3.3% (n=232,762) had a third-degree laceration and 1.1% (n=76,347) had a fourth-degree laceration. In an adjusted model for fourth-degree lacerations, important risk factors included shoulder dystocia and forceps and vacuum deliveries with and without episiotomy. Other demographic, obstetric, medical, and hospital variables, although statistically significant, were not major determinants of lacerations. Risk factors in a multivariable model for third-degree lacerations were similar to those in the fourth-degree model. Regression analysis of hospital rates (n=3,070) of lacerations demonstrated limited between-hospital variation.
Risk of third-degree and fourth-degree laceration was most strongly related to operative delivery and shoulder dystocia. Between-hospital variation was limited. Given these findings and that the most modifiable practice related to lacerations would be reduction in operative vaginal deliveries (and a possible increase in cesarean delivery), third-degree and fourth-degree laceration rates may be a quality metric of limited utility.
研究经阴道分娩女性发生三度和四度会阴裂伤的模式及预测因素。
我们利用全国住院患者样本，确定了1998年至2010年间在美国经阴道分娩的基于人群的队列女性。建立多变量对数线性回归模型，以考虑与裂伤相关的患者、产科和医院因素。使用广义对数线性混合模型计算医院间裂伤率的变异性。
在3070家医院接受阴道分娩的7096056名女性中，3.3%（n = 232762）发生三度裂伤，1.1%（n = 76347）发生四度裂伤。在四度裂伤的校正模型中，重要的危险因素包括肩难产以及使用产钳和真空吸引器分娩（无论是否行会阴切开术）。其他人口统计学、产科、医学和医院变量虽然具有统计学意义，但并非裂伤的主要决定因素。三度裂伤多变量模型中的危险因素与四度模型相似。对医院裂伤率（n = 3070）的回归分析表明，医院间差异有限。
三度和四度会阴裂伤风险与手术分娩和肩难产密切相关。医院间差异有限。鉴于这些发现以及与裂伤最相关的可改变做法是减少阴道手术分娩（以及可能增加剖宫产），三度和四度裂伤率可能是效用有限的质量指标。
