Combs C A, Robertson P A, Laros R K
Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco.
Am J Obstet Gynecol. 1990 Jul;163(1 Pt 1):100-4. doi: 10.1016/s0002-9378(11)90678-4.
Third- and fourth-degree perineal lacerations occur frequently during operative vaginal deliveries. To identify risk factors for lacerations, 2832 consecutive forceps and vacuum extraction deliveries were analyzed. Third- and fourth-degree lacerations occurred in 30% of deliveries. Multiple logistic regression was used to control for intercorrelation between potential risk factors. Factors associated with increased risk for third- and fourth-degree lacerations were midline episiotomy, nulliparity, second-stage arrest, occipitoposterior position, low or mid station, use of forceps instead of vacuum, use of local anesthesia, and Asian race. When these factors were controlled, there was no effect of birth weight, faculty versus resident operator, gestational age, abnormalities of first-stage labor, or several other factors. Prevention of perineal lacerations requires that the operator identify the patient at risk. Possible options for management of high-risk patients include use of mediolateral episiotomy or no episiotomy, use of vacuum extraction instead of forceps, and use of conduction anesthesia.
在阴道助产分娩过程中，三度和四度会阴裂伤很常见。为了确定裂伤的危险因素，对连续2832例产钳和真空吸引分娩进行了分析。30%的分娩发生了三度和四度裂伤。采用多元逻辑回归来控制潜在危险因素之间的相互关联。与三度和四度裂伤风险增加相关的因素有会阴正中切开术、初产、第二产程停滞、枕后位、低位或中位、使用产钳而非真空吸引、使用局部麻醉以及亚洲人种。当控制这些因素后，出生体重、教员与住院医师操作、孕周、第一产程异常或其他几个因素均无影响。预防会阴裂伤要求操作者识别有风险的患者。对高危患者可能的处理选择包括采用会阴侧切术或不做会阴切开术、使用真空吸引而非产钳以及使用传导麻醉。
