title: Incidence and risk factors for severe perineal laceration after vaginal delivery in Japanese patients.
abstract: OBJECTIVE
  The aim of this study was to assess the frequency of severe perineal lacerations defined as either third- or fourth-degree lacerations during normal spontaneous vaginal delivery and to evaluate potential risk factors in Japanese patients.
  
  
  METHODS
  An electronic audit of the perinatal database at the Tama-Nagayama Hospital of Nippon Medical School and Yamaguchi Hospital from 1997 through 2004 was completed. Singleton vaginal vertex deliveries were analyzed for potential risk factors using univariate and multivariate logistic regression analysis.
  
  
  RESULTS
  From the database, 7,946 deliveries were identified, with 135 deliveries resulting in severe lacerations (1.7%). In the multivariate logistic regression analysis, severe lacerations were associated significantly with primiparous (odds ratio, 4.36; 95% CI, 2.17-9.57), oxytocin use (odds ratio, 2.19; 95% CI, 1.27-3.73), midline episiotomy (odds ratio, 4.68; 95% CI, 2.09-11.55), forceps-assisted delivery (odds ratio, 7.11; 95% CI, 1.95-20.59), vacuum-assisted delivery (odds ratio, 5.93; 95% CI, 3.38-10.36), and shorter attendant experience (odds ratio, 2.88; 95% CI, 1.12-9.81).
  
  
  CONCLUSIONS
  The present study demonstrated that operator factors, such as midline episiotomy, oxytocin use, assisted delivery and attendant experience, are independent risk for severe perineal lacerations after vaginal delivery in Japanese patients. The results suggest that midline episiotomy and assisted vaginal delivery, especially forceps-assisted delivery should be avoided in patients who are being delivered of a first child whenever possible.
authors.affiliation: Department of Obstetrics and Gynecology, Tama Nagayama, Hospital, Nippon Medical School, 1-7-1 Nagayama Tama-City, Tokyo 206-8512, Japan. nakai-3@nms.ac.jp
authors.forename: Akihito
authors.initials: A
authors.lastname: Nakai
authors.forename: Atsuko
authors.initials: A
authors.lastname: Yoshida
authors.forename: Satoru
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Ikuno
authors.initials: I
authors.lastname: Kawabata
authors.forename: Masako
authors.initials: M
authors.lastname: Hayashi
authors.forename: Akishige
authors.initials: A
authors.lastname: Yokota
authors.forename: Taichi
authors.initials: T
authors.lastname: Isozaki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Takeshita
mesh_terms: D000328:Adult; D044466:Asian People; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D015994:Incidence; D022125:Lacerations / Q000453:epidemiology*; D016015:Logistic Models; D010502:Perineum / Q000473:pathology*; D011247:Pregnancy; D012307:Risk Factors