Episiotomy increases perineal laceration length in primiparous women.

Nager CW, Helliwell JP.

Department of Reproductive Medicine, The University of California, San Diego
Medical Center, 92103-8433, USA.

OBJECTIVE: The aim of this study was to determine the clinical factors that
contribute to posterior perineal laceration length. STUDY DESIGN: A prospective
observational study was performed in 80 consenting, mostly primiparous women
with term pregnancies. Posterior perineal lacerations were measured immediately
after delivery. Numerous maternal, fetal, and operator variables were evaluated
against laceration length and degree of tear. Univariate and multivariate
regression analyses were performed to evaluate laceration length and parametric
clinical variables. Nonparametric clinical variables were evaluated against
laceration length by the Mann-Whitney U test. RESULTS: A multivariate stepwise
linear regression equation revealed that episiotomy adds nearly 3 cm to perineal
lacerations. Tear length was highly associated with the degree of tear (R =
0.86, R(2) = 0.73) and the risk of recognized anal sphincter disruption. None of
35 patients without an episiotomy had a recognized anal sphincter disruption,
but 6 of 27 patients with an episiotomy did (P <.001). Body mass index was the
only maternal or fetal variable that showed even a slight correlation with
laceration length (R = 0.30, P =.04). CONCLUSION: Episiotomy is the overriding
determinant of perineal laceration length and recognized anal sphincter
disruption.

PMID: 11518907 [PubMed - indexed for MEDLINE]