From the Georgetown University Hospital, MedStar Health, Washington, DC; the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; MetroHealth Medical Center, Case Western Reserve University, Cleveland, Ohio; Indiana University Clarian Health, Indianapolis, Indiana; University of Miami, Miami, Florida; University of Texas Health Science Center at Houston, Houston, Texas; Maimonides Medical Center, Brooklyn, New York; University of Illinois at Chicago, Chicago, Illinois; Intermountain Healthcare and the University of Utah, Salt Lake City, Utah; Tufts University, Baystate Medical Center, Springfield, Massachusetts; Cedars-Sinai Medical Center, Los Angeles, California; Christiana Care Health System, Newark, Delaware; Summa Health Systems, Akron City Hospital, Akron, Ohio; and the EMMES Corporation, Rockville, Maryland.
Obstet Gynecol. 2011 Mar;117(3):627-635. doi: 10.1097/AOG.0b013e31820afaf2.
To characterize potentially modifiable risk factors for third- or fourth-degree perineal lacerations and cervical lacerations in a contemporary U.S. obstetric practice.
The Consortium on Safe Labor collected electronic medical records from 19 hospitals within 12 institutions (228,668 deliveries from 2002 to 2008). Information on patient characteristics, prenatal complications, labor and delivery data, and maternal and neonatal outcomes were collected. Only women with successful vaginal deliveries of cephalic singletons at 34 weeks of gestation or later were included; we excluded data from sites lacking information about lacerations at delivery and deliveries complicated by shoulder dystocia; 87,267 and 71,170 women were analyzed for third- or fourth-degree and cervical lacerations, respectively. Multivariable logistic regressions were used to adjust for other factors.
Third- or fourth-degree lacerations occurred in 2,516 women (2,223 nulliparous [5.8%], 293 [0.6%] multiparous) and cervical lacerations occurred in 536 women (324 nulliparous [1.1%], 212 multiparous [0.5%]). Risks for third- or fourth-degree lacerations included nulliparity (7.2-fold risk), being Asian or Pacific Islander, increasing birth weight, operative vaginal delivery, episiotomy, and longer second stage of labor. Increasing body mass index was associated with fewer lacerations. Risk factors for cervical lacerations included young maternal age, vacuum vaginal delivery, and oxytocin use among multiparous women, and cerclage regardless of parity.
Our large cohort of women with severe obstetric lacerations reflects contemporary obstetric practices. Nulliparity and episiotomy use are important risk factors for third- or fourth-degree lacerations. Cerclage increases the risk for cervical lacerations. Many identified risk factors may not be modifiable.
描述当代美国产科实践中三度或四度会阴裂伤和宫颈裂伤的潜在可改变风险因素。
安全分娩联合会从 12 个机构的 19 家医院收集电子病历（2002 年至 2008 年期间共有 228668 例头位单胎阴道分娩）。收集患者特征、产前并发症、分娩和母婴结局等信息。仅纳入 34 周及以上足月、成功阴道分娩头位单胎的女性，排除分娩时缺乏会阴裂伤信息和肩难产的资料，分别对 87267 例和 71170 例女性进行三度或四度会阴裂伤和宫颈裂伤分析。采用多变量逻辑回归校正其他因素。
共有 2516 例女性（2223 例初产妇[5.8%]，293 例经产妇[0.6%]）发生三度或四度会阴裂伤，536 例女性（324 例初产妇[1.1%]，212 例经产妇[0.5%]）发生宫颈裂伤。三度或四度会阴裂伤的风险因素包括初产妇（7.2 倍风险）、亚裔或太平洋岛民、出生体重增加、经阴道助产、会阴切开术和第二产程延长。随着体重指数增加，裂伤减少。宫颈裂伤的危险因素包括产妇年龄较小、经阴道使用真空吸引器、经产妇使用催产素，无论产次如何，行宫颈环扎术均增加宫颈裂伤的风险。
本研究中严重产科裂伤的大样本反映了当代产科实践。初产妇和会阴切开术是三度或四度会阴裂伤的重要危险因素。宫颈环扎术增加了宫颈裂伤的风险。许多已确定的风险因素可能无法改变。
