Labrecque M, Baillargeon L, Dallaire M, Tremblay A, Pinault J J, Gingras S
Department of Family Medicine, Laval University, Quebec.
CMAJ. 1997 Mar 15;156(6):797-802.
To evaluate the association between median episiotomy and severe (third- and fourth-degree) perineal lacerations in primiparous women.
Retrospective cohort study.
University-affiliated hospital providing secondary obstetric care in Quebec City.
A total of 6522 primiparous women who gave birth vaginally to a single live baby in cephalic position between 1985 and 1993.
Incidence of third- and fourth-degree perineal lacerations.
Median episiotomy was performed in 4390 women (67.3%). A total of 1002 women (15.4%) had a third- or fourth-degree laceration. The frequency of severe perineal lacerations was 20.6% with episiotomy and 4.5% without episiotomy (relative risk [RR] 4.58, 95% confidence interval [CI] 3.74-5.62). This association persisted after adjustment by stratified analysis for type of delivery and birth weight (RR 3.03, 95% CI 2.52-3.63) and by logistic regression for type of delivery, birth weight, epidural analgesia, shoulder dystocia, baby's head circumference, experience of the physician and year of delivery (odds ratio 3.58, 95% CI 2.84-4.50).
Median episiotomy is strongly associated with third- and fourth-degree perineal lacerations in primiparous women. Reducing the use of this procedure could decrease the occurrence of severe perineal tears.
评估初产妇正中会阴切开术与严重（三度和四度）会阴裂伤之间的关联。
回顾性队列研究。
魁北克市一所提供二级产科护理的大学附属医院。
1985年至1993年间共6522例初产妇，她们经阴道分娩单胎头位活婴。
三度和四度会阴裂伤的发生率。
4390例女性（67.3%）接受了正中会阴切开术。共有1002例女性（15.4%）发生了三度或四度裂伤。会阴切开术组严重会阴裂伤的发生率为20.6%，未行会阴切开术组为4.5%（相对危险度[RR]4.58，95%置信区间[CI]3.74 - 5.62）。经按分娩方式和出生体重进行分层分析调整后（RR 3.03，95% CI 2.52 - 3.63），以及经对分娩方式、出生体重、硬膜外镇痛、肩难产、婴儿头围、医生经验和分娩年份进行逻辑回归分析调整后（优势比3.58，95% CI 2.84 - 4.50），这种关联依然存在。
初产妇正中会阴切开术与三度和四度会阴裂伤密切相关。减少该手术的使用可能会降低严重会阴撕裂的发生率。
