Perineal Injury in Nulliparous Women Giving Birth at a Community Hospital: Reduced Risk in Births Attended by Certified Nurse-Midwives

Abstract

Our objective was to determine if there is a difference in rates of perineal injury sustained by nulliparous women attended by obstetricians compared with certified nurse-midwives (CNMs) at a US community hospital. We analyzed retrospective data for 2819 women who spontaneously gave birth to singleton, vertex, term, live infants between 2000 and 2005. The independent variable was attendant type (obstetrician or CNM). The main outcome variables were intact perineum, episiotomy, and spontaneous perineal lacerations. Multivariate logistic regression was used to adjust for six potential confounders: macrosomia, maternal age, epidural anesthesia, oxytocin administration, medical insurance status, and ethnicity. The odds ratios (ORs) for obstetrician-attended births versus CNM-attended births were significant for a spontaneous minor perineal laceration versus intact perineum (OR = 1.82; 95% confidence interval [CI], 1.33-2.48), spontaneous major laceration versus intact perineum (OR = 2.29; 95% CI, 1.13-4.66), and episiotomy use versus no perineal injury, with or without extension (OR = 2.94; 95% CI, 2.01-4.29). We found that the prevalence and severity of perineal injury, both spontaneous and from episiotomy use, were significantly lower in CNM-attended births.