Influence of previous delivery mode on perineal trauma risk

Abstract

Influence of prior delivery mode on perineal trauma risk ObjectiveTo evaluate the impact of a previous pregnancy and delivery on perineal trauma rates in the subsequent vaginal birth. MethodsRetrospective cohort study. The perineal outcomes of secundiparous women with history of previous (first) delivery in one of three categories: failed operative vaginal delivery (FOVD) and second stage emergency caesarean section (EmCS); elective caesarean section (ELCS), and vaginal delivery (VD) with intact perineum, were compared with a control primiparous group. ResultsThe percentage OASIs at first vaginal delivery after prior FOVD+EmCS was 17.3%(n=9), 12.9%(n=18) after previous ELCS, and 0.6%(n=9) after prior VD maintaining an intact perineum, compared with 6%(n=1193) in the control primiparous group of women. Multivariate regression analysis demonstrated prior FOVD+EmCS and ELCS were associated with a statistically significant increased risk of OASIs of 180% and 110% when compared to control (odds ratio (OR): 2.80; 95% confidence interval (CI): 1.35-5.78 and OR: 2.10; 95%CI: 1.27-3.48) respectively. Prior VD with intact perineum was associated with a statistically significantly reduced risk of OASIs (OR: 0.09; 95%CI: 0.04-0.17). ConclusionsPrevious FOVD+EmCS and ELCS were associated with increased risk of OASIs in subsequent vaginal delivery compared to control, whilst previous VD with intact perineum was associated with decreased risk.